A Swede of Rwandan origin and a Rwandan national were held in custody Wednesday in Sweden under suspicion of involvement in the African country's 1994 genocide, prosecutors said.

"Two men have been arrested and are being questioned. They are suspected of participating in the genocide," Tora Holst, prosecutor in charge of the probe, told AFP.

A string of arrests of prominent Rwandan military figures, some of them close to the central African nation's inner circle of power, has prompted speculation of a major political crisis.

A South African court on Wednesday sentenced four men each to eight years in prison for trying to murder a Rwandan general, months after he fell out with President Paul Kagame.

Magistrate Stanley Mkhari found three Tanzanians and one Rwandan guilty of a "politically motivated" plot to kill General Kayumba Nyamwasa in June 2010.

A top Rwandan colonel and a retired general were charged Friday in a Kigali court for inciting rebellion by "spreading rumors".

The pair are the latest in a series of military men accused of challenging the rule of the country's strongman and president, Paul Kagame.

Fishermen in Burundi have found several corpses with limbs bound or stuffed in sacks, floating in a lake bordering Rwanda, government officials said Tuesday.

Some 40 bodies have been found in the lake since July, according to fisherman in the Burundian town of Giteranyi, the president of their association Sadiki Nyandwyi told Agence France Presse by telephone.

Authorities in Rwanda have arrested several senior and former top military figures, an official said Monday, in an apparent crackdown against internal critics of the country's strongman and president, Paul Kagame.

Army spokesman General Joseph Nzabamwita refused to say why three prominent military figures had been held, and referred queries to reports carried by the pro-government New Times newspaper.

The United States warned Tuesday that the last major illegal armed group in eastern Democratic Republic of Congo must surrender in "significant" numbers soon or face military action to eliminate it.

Russ Feingold, the special U.S. envoy to Africa's Great Lakes Region, said officials from the region will meet at the United Nations Thursday to discuss how to proceed against the Democratic Forces for the Liberation of Rwanda (FDLR), a rebel group formed by Hutus who fled Rwanda in 1994.

Rwandan President Paul Kagame named the former labor minister Anastase Murekezi as the new prime minister on Wednesday, a presidential statement said.

The appointment is expected to bring in a possible cabinet reshuffle, as under Rwanda's constitution, ministers must be chosen -- or reappointed -- by the new prime minister.

The U.N. court for Rwanda upheld a 30-year jail term for former army chief Augustin Bizimungu on Monday for his role in the 1994 genocide during which he called for the murder of minority Tutsis.

The International Criminal Tribunal for Rwanda (ICTR) "unanimously affirmed the sentence of 30 years in prison," Judge Theodor Meron said, as the former general stood to hear his appeal dismissed in the courtroom in Tanzania.

A Swedish court upheld the conviction Thursday of a man of Rwandan origin who was sentenced last year to life in jail for his part in the 1994 genocide.

Stanislas Mbanenande, an ethnic Hutu, was convicted by a Stockholm district court for his role in the mass murder of Tutsis in Rwanda.