At least 10 people have been killed in Burundi during an attack on a convoy of vehicles travelling towards the capital, Bujumbura.

The attack is reported to have taken place at Kangunzi, 55 kilometres north-west of the capital.

Most of the vehicles were buses, and there are reports that many passengers were injured.

The army say they have been chasing rebels of the Forces for the Defence of Democracy (FDD) in the area.

The FDD signed a ceasefire with the government in December, and a spokesman has denied his group is responsible for the ambush.

Steal to survive

The vehicles, which were travelling from Cibitoke to Bujumbura on Monday morning, were ambushed by unidentified armed men.

"The rebels sprayed the vehicles with bullets to stop them, then they searched everyone for money, luggage and anything that could be taken away," a wounded survivor was quoted as saying by the French news agency, AFP.

The BBC's Prime Ndikumagenge in Bujumbura says attacks like this are not isolated incidents.

The army is dominated by ethnic Tutsis

He quotes rebels as saying they have to kill and steal to survive.

The other main rebel group, the National Liberation Forces (FNL), have also denied carrying out the attack.

But the FNL says breakaway elements of the FNL have mingled with Mayi-Mayi militias from DR Congo who have been launching raids in western Burundi.

Peace talks

In a separate incident, 40 fishing boats have been attacked by rebels on Lake Tanganyika, south of Bujumbura, AFP quotes a local official as saying.

The rebels, who had come from the Democratic Republic of Congo in several dugout boats, stole engines, fishing nets and clothes from the crews.

The official blamed the attack on Mayi-Mayi militias and FDD rebels.

Meanwhile the chief mediator in the conflict, the South African deputy president, Jacob Zuma, has left for Ethiopia.

An African Union meeting is due to be held in Addis Ababa on Tuesday to discuss the situation in Burundi.