KAMPALA, Uganda — A Ugandan pop star-turned-opposition lawmaker flew out of the country for medical treatment after alleged torture while in detention, his lawyer said, a day after security forces blocked him from boarding a flight to the U.S. and set off a new round of protests.

Bobi Wine, whose real name is Kyagulanyi Ssentamu, departed Entebbe International Airport on a KLM flight near midnight after authorities said they had given him the necessary clearance, Nicholas Opiyo said on Twitter.

Video posted by Opiyo showed the 36-year-old singer in his trademark red beret and carrying crutches as he was wheeled to the departure gate, saluting and thanking supporters along the way. It was not immediately clear where he was headed.

The actions by security forces against Ssentamu escalated a political dispute between the government of longtime President Yoweri Museveni and a youthful generation that fears he intends to rule for life after 32 years in power.

The drama began earlier this month when Ssentamu and several other lawmakers were charged with treason over an incident in which the president's motorcade was pelted with stones.

Another lawmaker who was blocked on Thursday from flying to India for treatment, Francis Zaake, was still being held in a hospital Friday night.

Ssentamu had been stopped Thursday night while trying to board a U.S.-bound flight and was checked into a hospital in the capital, Kampala, in a "worrying condition," according to another of his lawyers, Asuman Basalirwa.

Authorities said a government medical board had to examine Ssentamu before any travel abroad because of the claims of torture, which security forces have denied.

The singer was freed on bail on Monday but faced no travel restrictions after he and other lawmakers were charged. His lawyers say the treason charges are false.

Ssentamu has emerged as a powerful opposition voice among youth frustrated by Museveni, especially after the constitution was changed last year to remove an age limit on the presidency. The singer won a parliament seat last year without the backing of a political party.

Dozens of global musicians including Chris Martin, Angelique Kidjo and Brian Eno last week issued an open letter condemning the treatment of Ssentamu, who in his first public appearance after his arrest had to walk with support and appeared to cry.

Ssentamu and Zaake both have alleged serious injuries at the hands of security forces during detention. The government denies it.

The treason charges have heightened concerns about a crackdown on the opposition in this East African nation. Security forces earlier Friday deployed heavily in Kampala's Kamwokya neighborhood against protesters.

"If a member of parliament can be treated like that, what of me who is on the street now?" asked one Kampala resident, Charles Ssenyange.

The 74-year-old Museveni, a close U.S. security ally, has held power since 1986. He has spoken in recent days about "unprincipled politicians taking advantage of our unemployed youth to lure them into riots and demonstrations."