Uganda's Bobi Wine picked up by police on arrival home from US

Ugandan security forces swiftly took pop star and opposition lawmaker Bobi Wine into custody when he arrived from the United States on Thursday, further angering supporters who have protested his alleged torture by security forces and a treason charge.

The singer, who has emerged as a popular voice against longtime President Yoweri Museveni, one of Africa's longest-serving leaders, was "unlawfully detained by military officers," his US-based lawyer Robert Amsterdam said on Twitter. National police chief Okoth Ochola, however, said he was taken to his home and was not under arrest.

The singer, under police escort, was driven to his residence outside the capital, Kampala, where hundreds of youthful supporters cheered and chanted as he climbed on top of a car and raised his fist.

TRT World producer Adesewa Josh explains how opposition lawmaker Bobi Wine poses a danger to the current establishment in Uganda.

A threat to the establishment?

Bobi Wine, whose real name is Kyagulanyi Ssentamu, had sought treatment in the US for injuries allegedly sustained during torture by members of the presidential guard, which Uganda's government denies.

Ahead of his return, security forces set up barriers near the airport and elsewhere around the capital amid heavy security. Police detained the singer' s brother and at least two other people who were driving to the airport, without explanation, lawyer Asuman Basalirwa said.

Police also surrounded the home of Kampala Mayor Erias Lukwago, and he was unable to leave, said another of the singer's lawyers, opposition legislator Medard Sseggona.

Longtime opposition leader Kizza Besigye, who has been arrested many times over the years, said on Twitter that it is likely Ssentamu "will now be blockaded at home till further notice."

The singer, who won a national assembly seat last year, faces treason charges over his alleged role in an incident last month in which the president's convoy was pelted with stones.

He denies wrongdoing. His next court appearance is October 1.

The 36-year-old Ssentamu says he is fighting for freedom from oppression and wants Museveni, in power since 1986, to retire. Museveni, in turn, has accused opposition figures of trying to lure Uganda's youth into rioting.

Ssentamu has a big following among the poor and unemployed in urban areas. His arrest last month sparked riots by demonstrators demanding his release and security forces violently put down protests in the capital.

Dozens of global musicians have condemned the treatment of the singer, and the European Union parliament and some US senators have urged Ugandan authorities to respect basic human rights.

Museveni, a key US ally on regional security, took power by force and has since been elected five times. Although he has campaigned on his record of establishing peace and stability, some worry those gains are being eroded the longer he stays in power.