As the sentencing of her husband, Blake Fielder-Civil, nears, Amy Winehouse has been accused of lashing out at a stranger - for the third time in two weeks.

In the most recent altercation, she reportedly punched a fellow drinker at Camden’s Dublin Castle pub in what was claimed was an unprovoked attack.

“She was in front of me at the bar and suddenly turned and walloped me three times across the face. It really stung,” Wayne Lindsay, 29, told Britain’s Daily Mirror. “I couldn’t believe it. I hadn’t said a word to her or touched her.”

A source close to the singer tells PEOPLE that Winehouse merely reacted because someone grabbed her from behind - and that her security then stepped in. (The insider added that she has felt an increasing need for bodyguards in recent weeks.)

On July 7, Winehouse reportedly hit another fan who was trying to photograph her as she returned to her home.

Both incidents follow the widely-documented episode in which the star struck out at a fan during the Glastonbury festival.

Her rep declined to comment.

Amy Winehouse has left the hospital, it was confirmed Tuesday.

The performer, who had a busy weekend of concerts, was discharged from the clinic where she has been staying for more than 10 days on Monday.

Her representative, Chris Goodman, said, “She has left %26#91;the%26#93; hospital. She is continuing as an outpatient.”

“She will return for regular appointments for check%26#91;-up%26#93;s,” said Goodman.

He adds, “There comes a time when you are ready to leave the hospital, and so she left. No one was trying to keep her there. It was completely up to her - everyone knew she would not stay there forever.”

Despite some controversy over her performance at the rock festival - it was reported the singer allegedly took a swing at an audience member - Goodman says Winehouse is “looking great and feeling great.”

Amy Winehouse is back on stage - and she’s in fighting form.

At the end of her hour-long performance Saturday before nearly 80,000 festivalgoers at the Glastonbury Festival in Somerset, England, the singer climbed down from the Pyramid stage and threw a punch at a fan, the Associated Press reports.

Witnesses say that a fan tried to grab the singer, though it is unclear what provoked the altercation.

The beleaguered Brit, 24, then mumbled a bit, and told the crowd: “I’ve only got two weeks left of this predicament, so this one’s for you, Blake.”

Following her performance, Winehouse changed into more casual clothes - a striped T-shirt and shorts - before scouting out a headlining set by rapper Jay-Z, which she watched next to his wife, Beyoncé.

Earlier in the weekend, Winehouse surprised fans with a two-song performance as part of Nelson Mandela’s 90th birthday tribute in London’s Hyde Park.

The singer looked healthy, according to reports, and gave her husband some attention with a heart-shaped adornment that featured his name, which she wore in her hair.

Amy Winehouse was back on stage in London Friday when she performed rousing renditions of two of her hits at a special concert as part of Nelson Mandela’s 90th birthday tribute.

Wearing a white-and-black form-fitting dress, the Back to Black singer, 24, sang “Rehab” and her massive hit “Valerie” for the crowd, who welcomed her with loud cheers.

Despite her recent hospitalization, Winehouse looked healthy. She wore her trademark beehive loose at the back. Decorating her hair was a heart-shaped adornment inscribed with “Blake” for her incarcerated husband, Blake Fielder-Civil.

A surprise guest spotted in the crowd was Prince William’s girlfriend Kate Middleton.

The first that the crowd saw of Winehouse was at about 8:30 p.m. when she joined the rest of the performers to listen to Mandela make a brief speech. The concert also raises awareness for his 46664 charity and campaign, named after Mandela’s prison number. “Our work is for freedom for all,” Mandela said.

Led by Will and Jada Pinkett Smith, Winehouse joined performers and guests such as Geri Halliwell, Leona Lewis and Annie Lennox on stage to sing “Happy Birthday” to Mandela, with Lennox blowing a kiss to the statesman as he left the stage.

Winehouse also took lead vocals in a version of “Free Nelson Mandela,” alongside Jerry Dammers, the writer of the ’80s anthem, and most of the concert’s performers, including rockers Queen.

Amy Winehouse has been tested for tuberculosis during her prolonged hospital stay, her rep tells PEOPLE.

“She has a chest infection and she had a routine test for TB, which came back negative,” Chris Goodman tells PEOPLE.

Goodman also denies a report - in U.K. tabloid The Sun - that she has been coughing up blood at the London clinic where she was taken after fainting earlier this week.

“She would really love to do the show - she always wants to do these things,” said Goodman. “But she will listen to her doctors.”

Amy Winehouse is undergoing further hospital tests in the wake of her collapse Monday in her London home,

The soul diva, 24, was given additional scans and tests Thursday, says her rep, Chris Goodman, the Associated Press reports.

Winehouse is due to perform June 27 at a concert marking Nelson Mandela’s 90th birthday. The next day she is supposed to participate in England’s Glastonbury music festival.

Goodman says both dates remain in place, though a final decision “will be made entirely on the advice of her doctors and in her best interests.”
- Stephen M. Silverman

Amy Winehouse has had very public problems, but she’s had no trouble filling her schedule with high-profile performances.

The troubled singer will sing at the 46664 Concert celebrating Nelson Mandela’s 90th birthday at London’s Hyde Park on June 27. The concert features an all-star lineup of Leona Lewis, Annie Lennox, Dame Shirley Bassey, Razorlight and more than a dozen South African musicians.

A spokesperson for Winehouse says that she is “proud” and “honored” to add her voice in support of 46664, which seeks to raise awareness about the impact of AIDS and the importance of HIV prevention.

Tim Massey, the International Director of 46664, said in a statement, “We are delighted that Amy will be appearing at Hyde Park to celebrate Nelson Mandela’s 90th birthday. Amy joins an illustrious list of names showing their support for 46664 and the fight against AIDS.”

It’ll be a busy week for Amy, 24, who will take the stage the following day at Glastonbury Music Festival in Somerset, England.

The show will go on for Amy Winehouse, despite her recent laundry list of problems.

On June 28, the Grammy winner is expected to be one of the star attractions at this year’s Glastonbury Music Festival in Somerset, England, where she will hit the stage directly before headliner Jay-Z, reports the BBC.

Despite a certain degree of unreliability in Winehouse’s past - her on-again, off-again Grammy appearance, as well as the question of whether she’d be in shape to deliver the new James Bond theme, for instance - “I have total faith, I think she’ll come and deliver,” Glastonbury rep Emily Eavis is quoted as saying.

June 28 falls smack dab in the middle of the three-day fest. “Glasto” as the performing arts festival is commonly nicknamed, is the largest outdoor celebration of its kind in the world.

Of the singer’s private problems, Eavis said, “It’s her personal life and no one really knows the extent of what she’s up to and I don’t think it should be public knowledge. We all know she’s a brilliant performer and I think that’s what we should be focusing on.”

Besides Glasto, Winehouse, 24, is also slated to play several engagements across Europe, including Portugal’s Rock in Rio (this coming Friday), Ireland’s Oxegen Rock en Seine in Paris and Bestival on the Isle of Wight on Sept. 6.

Amy Winehouse remained hospitalized Tuesday morning after tests on the troubled singer - who fainted in her London home on Monday - proved “inconclusive,” a source close to the singer tells PEOPLE.

The 24-year-old’s father, Mitch, drove her to the hospital in his taxi after she fainted and nearly fell down a flight of stairs. Though she recovered quickly, her spokesman said she was examined as a precaution. Originally, she was expected to be released today.

“Doctors want to get to the bottom of it before releasing her,” Winehouse’s London spokesman told PEOPLE. “There will be further tests and they will keep her under observation. She seems to be fine … but they are taking their time to be sure.”

“She didn’t want to get clean then, but she’s talking about it now,” he told the U.K.’s Closer magazine. “She’s nowhere near as bad as she was %26#91;then%26#93;. A nurse visits twice a day and we’re kept well informed about how she’s doing. She’s making progress.”

Mitch, 57, said the singer wants kids with her jailed husband Blake Fielder-Civil - and will wait for him.

“Amy understands Blake might have to do a long time in prison - she’s not stupid,” he told the magazine. “But she’ll stand by him and he’ll stand by her.” (Earlier this month, Fielder-Civil pleaded guilty to charges of assault and attempting to pervert the course of justice.)

Mitch added: “She wants kids and knows she can’t be taking drugs, or the baby would be addicted - she wouldn’t do that.”

Amy Winehouse fainted in her London home Monday and was taken to the hospital, her spokesman confirms to PEOPLE.

Though she “quickly recovered” from not feeling well, the soul diva, 24, did require her manager’s assistant “to stop her falling” in her home, her rep said, according to the BBC. The singer’s father, Mitch Winehouse, accompanied her to the hospital “as a precaution,” according to the rep.

He told PEOPLE: “She’s fine. It was a brief thing and they took her in as a precaution. Her Dad drove her to a private hospital, but they’re unsure what caused it so aren’t taking any chances.”

Winehouse apparently passed out after she was about to sign autographs for some Canadian fans who’d been waiting outside her home all day. When she went to see them, said her rep, she discovered they had gone. It was then that she fainted.