Updated

Police have warned some Rwandan exiles living in Britain that their lives are in danger, issuing letters of concern after the men criticized the government of the east African nation.

Rene Mugenzi, who fled to Britain after the Rwandan genocide, said he had received a "threat to life" warning from London's Metropolitan police — an official letter that warns recipients that their personal safety is under threat. Police do not usually reveal the sources of their concern.

"They told me my life is in immediate danger," he told The Associated Press. "They based their warning on intelligence they had received, and gave me some advice on how to improve my security."

Mugenzi, who is chief executive of a London think-tank, the London Center for Social Impact, said he believes he crossed the Rwandan government after he gave an interview to the BBC on whether the recent uprisings in northern Africa against despotic rulers were relevant to Rwanda, and made some comments critical of Rwandan President Paul Kagame.

"I made some comments on whether an Arab Spring could happen in Rwanda and I heard that it made Paul Kagame very angry," he said.

Mugenzi said he believed other Rwandans had also received similar warnings from police. Mugenzi, who has lived in Britain for 15 years, received his warning on May 12.

Kagame is renowned for his role in helping to end the 1994 genocide during which extremist Hutus killed more than 500,000 Tutsis and moderate Hutus. But his democratic credentials have been questioned, as has his ability to heal his nation's ethnic divide.

He was re-elected last year after opposition parties were banned from the vote and some Rwandans said they were forced to cast ballots for him. Freedom House noted a "severe crackdown on opposition politicians, journalists and civil society activists in the run-up to a deeply flawed August 2010 presidential election.

Mugenzi said he had not received any direct threats or messages from the Rwandan government, but noticed that the Rwandan High Commission had sent observers to photograph people who attended a conference he organized in April to promote peace in the Great Lakes region, which includes Rwanda, Congo, Angola, the Central African Republic, Sudan, Uganda and Burundi.

London's Metropolitan Police said it would not comment on individual cases but said in a statement that it takes "all threats against persons extremely seriously."

The British government is one of the biggest donors and supporters of the Rwandan government and gave 52.8 million pounds (US$85.7 million) in aid to the country in 2009/2010. The Foreign Office refused to comment on individual cases, but said in a statement that it does address matters of human rights with the Rwandan government.

"We take every opportunity to raise with the Rwandan Government our concerns over political space, media freedom and extra-judicial killings," the statement said. "We continue to urge the Government of Rwanda to address these issues and to bring the perpetrators of human rights abuses to justice."

Earlier this year, Kagame's former attorney general, intelligence chief, army chief and chief of staff all were convicted earlier this month by a Rwandan military court of disturbing public order, threatening state security, sectarianism and criminal conspiracy. The men fell out with Kagame after criticizing his ability to deliver democracy and stability in his country.

Telephone calls to the Rwandan High Commission in London were not returned.