Ugandan pop star and MP Bobi Wine has been released from hospital and is flying out of the country for medical treatment in the US, police say.

It follows claims the MP was severely beaten while in military custody, allegations denied by the army.

He, and 32 opposition politicians, were charged with treason last week over the alleged stoning of President Yoweri Museveni's convoy.

Bobi Wine was earlier granted bail but was told he could not leave Uganda.

On Friday, police confirmed that he had been cleared to fly out of the country for specialised treatment after the government sent a team of nine doctors to examine him.

Bobi Wine's lawyer earlier said the pop star had been violently re-arrested at the airport on Thursday "even though the judge had let him have his passport because he needed to leave the country for medical reasons".

"He was violently thrown into a police ambulance. The lawyers have no idea where he is being taken and we're all really in shock," Robert Amsterdam told the BBC's Newsday programme.

A police spokesman said on Twitter that Bobi Wine was being given a medical examination because of the allegations of torture.

They also said that another opposition MP, Francis Zaake, who was also trying to go abroad for treatment, had been "trying to flee the country and accordingly apprehended him".

Meanwhile, supporters of Bobi Wine have held protests in the capital, Kampala.

Pictures shared on social media show plumes of smoke rising in the capital, with local media reporting that the protests are confined to Kamwokya slum, where the MP grew up.

Bobi Wine, whose real name is Robert Kyagulanyi, appeared on crutches during Monday's court appearance. His allies say he was tortured by elite presidential guards during his detention.

The army have described the allegations as "rubbish" and a police spokesperson told the BBC that the authorities want to carry out their own medical tests.

His aides say he was re-arrested at Uganda's main international airport where he was planning to board a plane to Washington to seek further medical treatment.

"He's in tremendous pain and suffered very serious injuries," Mr Amsterdam said of the star's condition. "There's not a part of his body that isn't in pain."

"His children were going to stay in Uganda. It was a brief trip, simply for a medical evaluation," he said.

What led to the treason charges?

Before being arrested, Bobi Wine tweeted a gruesome picture of his driver, who he said had been shot dead by police thinking he was the MP.

Bobi Wine was arrested on 13 August after a campaign rally in the north-western town of Arua where the presidential convoy was allegedly stoned.

Image copyrightAFP

Image caption: Bobi Wine's supporters protested in Kampala last week

The 36-year-old musician was initially to be tried in a military court over accusations of unlawful possession of firearms but the charge was dropped. A civilian court later charged him with treason.

Bobi Wine, and the other accused, were expected to appear in court again on Thursday but the hearing has been adjourned to 1 October.

Who is Bobi Wine?

The Afrobeats star has been a thorn in the side of Mr Museveni's government. Since his election as an MP just over a year ago, he has backed candidates in three by-elections who have beaten those from the ruling National Resistance Movement (NRM), including in Arua.

He was also a leading campaigner against the move to scrap the presidential age limit - set at 75 - which would have locked out the 74-year-old Mr Museveni's bid to run for a sixth term in 2021.

Wine also joined local activists in July to protest against a social media tax introduced ostensibly to boost state revenue and to end what Mr Museveni called "gossip" on WhatsApp, Facebook and Twitter.

• Taxing 'gossip' on the internet

Critics, however, said the 200 Uganda shillings ($0.05, £0.04) daily tax was meant to suppress dissenting voices.

The government has since said it will review the tax.