Hundreds of refugees are fleeing the Democratic Republic of Congo (DRC) for Uganda to escape renewed attacks by armed rebels on the towns of Lubiriha and Kasindi.

A spokesperson for the Uganda People's Defence Force (UPDF) blamed the Mai Mai militia.

"We have corresponded with the commanders on the other side (DRC) and they say the Mai Mai rebels attacked the two towns overnight," Capt Peter Mugisa told the Ugandan Daily Monitor.

The term "Mai Mai" refers to a range of local and community-based militias who were active during the Congo's two wars between 1996 and 2003 and since.

They are among the most prolific recruiters and users of child soldiers.

The most recent attacks came as the UN Refugee Agency UNHCR said staff had witnessed tens of thousands of villagers being displaced in North Kivu province in DR Congo.

Widespread human rights abuses witnessed by UNHCR staff include rape and torture.

"We are talking specifically about indiscriminate and summary killings of civilians. We are talking about rape and other forms of sexual abuse - torture, arbitrary arrests, assaults, looting of food and money, destruction of property," spokesperson Andrej Mahecic said. "We are also talking about forced labour and forced recruitment, including children, and also ethnically motivated violence."

The UNHCR estimated more than 470,000 Congolese have fled their homes in eastern DRC since April.

"The current estimate of the internally displaced population in the DRC stands at a staggering 2.2 million people," Mahecic added.