Uganda's pop star politician Bobi Wine vowed on Thursday to continue his fight for more freedom in the country "or we shall die trying," shortly after security forces took him into custody on his arrival from the United States after treatment for alleged torture.The opposition lawmaker, 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 but was not under arrest.The singer, who faces a treason charge that he denies, 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."I didn't know where they were taking me," he later told reporters, describing security forces on his arrival. "They just grabbed me."Bobi Wine, whose real name is Kyagulanyi Ssentamu, had sought treatment in the US for injuries allegedly sustained during torture after arrest last month by members of the presidential guard, which Uganda's government denies.The singer, who won a national assembly seat last year, faces treason charges over his alleged role in an incident in which the president's convoy was pelted with stones. He denies wrongdoing and faces a court appearance October 1.Ahead of his return to Uganda, security forces set up barriers near the airport and elsewhere around the capital amid heavy security. Police detained his brother and at least two other people who were driving to the airport, without explanation, lawyer Asuman Basalirwa said.Longtime opposition leader Kizza Besigye, arrested many times over the years, said on Twitter that it is likely Ssentamu "will now be blockaded at home till further notice."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."It looks like the government is determined to keep us slaves in our own country," the singer told reporters at his home, adding that "I have come to continue exactly where I stopped. I am going to fight on." He said he will stay in Uganda because "I cannot be a refugee."Ssentamu, who clutched a cane and said he still felt pain and walks "with hardship," plans to say more at a press conference on Saturday.The singer 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.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.