Burundi faces mounting regional pressure to accept African Union peacekeepers it calls an "invasion force", diplomats said Wednesday, with the issue a key point of talks due in Uganda next week.

The 54-member African Union said last week it would send a 5,000-strong force to halt violence that has sparked fears Burundi is sliding back towards civil war, and has pledged to send troops despite Burundi's fierce opposition.

Rwanda President Paul Kagame praised Monday a constitutional referendum allowing him to rule until 2034, but did not declare whether he intends to run in the next election.

Kagame had previously said he would make a decision on standing in the 2017 polls only after results were in from Friday's referendum in which 98 percent of the population approved constitutional changes making his candidacy legal.

Rwanda has overwhelmingly voted to change the constitution to allow President Paul Kagame to potentially rule until 2034, election officials said on Saturday citing partial referendum results.

"We have seen the will of the people. It's clear that what the people want, they can achieve," said National Electoral Commission chief Kalisa Mbanda, announcing 98.1 percent had voted "yes" with preliminary results in from some 70 percent of the country.

Rwandans abroad were voting Thursday in a referendum to amend the constitution allowing President Paul Kagame to rule until 2034, a day ahead of the main vote inside the country.

The constitutional amendment, which was already passed by parliament last month, reduces presidential terms to five years and maintains a two-term limit, although it makes an exception for Kagame.

U.S.-based advocacy group Refugees International said that men and boys in Rwanda's Mahama camp, run by the United Nations and Rwandan authorities, were being recruited into "non-state armed groups" and faced threats if they refused.

The charity added that the Burundian recruits are trained in Rwanda and efforts are made to send them back to Burundi via neighboring Democratic Republic of Congo.

One of nine top fugitive Rwandan genocide suspects, a former mayor accused of slaughtering thousands of people and organizing mass rapes in 1994, has been arrested, the United Nations said.

Ladislas Ntaganzwa, who had a $5 million (4.6 million euro) U.S. bounty on his head, has been indicted by a U.N.-backed court for genocide and crimes against humanity.

Rwandan President Paul Kagame must set an example for his region and step down at the end of his term in 2017, the U.S. ambassador to the United Nations said Tuesday.

Samantha Power spoke after Rwanda's senate last month passed a constitutional amendment that would allow Kagame to run for a third term in 2017, and potentially remain in power for the next two decades.

Rwandan President Paul Kagame has accused Burundi's leaders of carrying out "massacres" on their people in his most critical speech yet of the crisis in the troubled neighboring state.

"People die every day, corpses litter the streets... How can the leaders allow their population to be massacred from morning to night?" Kagame said, speaking in Kinyarwanda on Friday, in a speech heard by AFP on Sunday.

A German court Monday sentenced two Rwandan rebel leaders to long jail terms for masterminding massacres in eastern Democratic Republic of Congo from their homes in Germany, capping a trial hailed by the U.N. as a breakthrough.

Ignace Murwanashyaka, head of the Democratic Forces for the Liberation of Rwanda (FDLR), received 13 years in prison, while his deputy Straton Musoni was given eight years, judge Juergen Hettich told the court after a trial that lasted more than four years.

A German court Monday sentenced two Rwandan rebel leaders to long jail terms for masterminding massacres in eastern Democratic Republic of Congo from their homes in Germany, capping a trial hailed by the U.N. as a breakthrough.

Ignace Murwanashyaka, head of the Democratic Forces for the Liberation of Rwanda (FDLR), received 13 years in prison, while his deputy Straton Musoni was given eight years, judge Juergen Hettich told the court after a trial that lasted more than four years.