Protests erupted in the Ugandan capital on Friday after police detained two lawmakers at the international airport as they prepared to travel abroad for medical care, witnesses said,

People demonstrated in different parts of Kampala, burning tyres and piling rocks and other barricades in the middle of the roads. Police said the protests were limited and had been contained.

The lawmakers, Robert Kyagulanyi and Francis Zaake, say they were tortured by security forces while in detention. They were trying to leave to seek medical treatment abroad when they were arrested at Kampala's international airport on Thursday night.

Kyagulanyi's lawyer last week told Reuters that his client had been left unable to stand after being beaten while in detention. When he appeared in court a day after his lawyer spoke, he was unable to walk without help.

Government spokesperson Ofwono Opondo last week dismissed the lawyer's comments as rubbish

Friday's demonstrations were most intense in Kamwokya, a suburb of Kampala where Kyagulanyi, a pop star known by his stage name Bobi Wine, has a recording studio, according to Dick Nvule, a local radio reporter.

"Protesters blocked the roads using garbage cans and burning tyres. Motorists have to get alternative routes to the city centre. Soldiers and riot police are still clearing the roads," Nvule told Reuters.

Police spokesperson Luke Owoyesigyire said police were monitoring the city to ensure no illegal rallies took place.

The two parliamentarians were among a group of five lawmakers who were detained on August 13 in Uganda's northwestern town of Arua and accused of throwing stones at a presidential convoy during the campaign for a parliamentary seat.

Police said on Thursday they had stopped Kyagulanyi, who has been charged with treason but released on bail, as they awaited further guidance.

Zaake has not been charged but has been in hospital in Kampala. Images of him posted on social media show him lying on a bed, eyes closed, with multiple bruises on his hand and other body areas.

Kyagulanyi in particular has risen as a formidable threat to President Yoweri Museveni's 32-year rule, winning popular support through his music and strong criticism of the government.