Rioters set fire to roadblocks in Kampala and clashed with police firing tear gas and live rounds, leaving two dead, scores injured and several hundred people arrested Friday.

The riots come one day after opposition leader Kizza Besigye was attacked with tear gas and had his car smashed by police who arrested him for the fourth time this month.

Ugandan authorities said they had arrested 360 people over Friday's riots as police "restored law and order."

Internal Affairs Minister Kirunda Kivejinja said the police force "within its constitutional mandate restored law and order" removing road blocks and "disengaging crowds" after the riots.

He refused to comment on the use of live rounds by security forces.

"That one we will have to investigate," he said.

The Ugandan Red Cross said two people had died from gunshot wounds and 143 others had been hospitalised, about a dozen, including a two-year-old girl, with gunshot wounds.

"Two people have been shot and died," Red Cross spokeswoman Catherine Ntabadde told AFP.

Besigye's arrest on Thursday came as he took part in a protest against rising food and fuel prices. A series of such protests this month have left five people dead.

Some Kampala residents linked Friday's riots to the treatment meted out to Besigye during his arrest, which was retransmitted on television.

"It is because Besigye was handled so badly during the arrest," said Robert Ssekandi, 41, a motorcycle taxi driver in downtown Kampala.

"How can they treat a human being like that? That is why we needed to take action," Ssekandi said.

Besigye was on Friday evening on a plane bound for Nairobi, where he will seek specialist treatment for the acute inflammation of the eyes brought on by his tear gas ordeal Thursday, one of his aides said.

Police said rioters using scrap and burning tyres had set up road blocks around a market area in the centre of the capital, drawing tear gas fire from a police and military police.

The rioting quickly spread to several suburbs, three towns outside the capital and Mbale, a town in the east.

In the casualty ward of Kampala's main hospital staff scrambled to cope with the influx of patients, with around 60 people in the surgical medical ward, some of them on mattresses on the floor.

Lying in a corridor with a bullet wound to his ankle, 15-year-old school pupil Julius Lubega said he had been shot by police.

"I was just coming from my home and that was when they got me," Lubega said.

Some patients told how they had received injuries at the hands of plain clothes security operatives.

"There were 10 of them, one policeman and around 10 men in plain clothes," Martin Trust, 21, an electrical appliance salesman said.

"I was innocent so I didn't run, then they got me and started beating me with batons and fists," Trust said, showing severe bruising on his face, head and torso.

An AFP photographer reported debris and heavy security deployment in several suburbs. The photographer said he saw live rounds fired at houses.

Besigye, who lost to President Yoweri Museveni for the third time in February elections he said were rigged, had only just been released from a week in custody.

Besigye and other opposition leaders earlier in April started walking to work twice a week as a symbolic protest against rising fuel costs but the demonstrations have met with a tough response from the police.

According to the Ugandan Red Cross, five people have died nationwide this month in violence.

Food and fuel prices have soared in the eastern African country recently, with Museveni blaming inflation on meteorological and global economic factors, but protestors see it as a result of bad governance.