Former Liberian president Charles Taylor has formally applied to serve the rest of his jail term for war crimes in Rwanda, saying his imprisonment in Britain breaches his human rights, his lawyer said Thursday.

Taylor was jailed for 50 years in 2012 on 11 counts of war crimes and crimes against humanity over acts committed by Sierra Leonean rebels he aided and abetted during the brutal 1991-2001 civil war.

Fighting flared again on the border of Rwanda and the Democratic Republic of Congo early on Thursday, the second day of skirmishes between two neighbors locked in a decades-long dispute.

Rwandan and Congolese troops traded heavy weapons fire around 8:00 am (0600 GMT), said a resident and an administrative official in Kanyeshaza, about 20 kilometers (12 miles) northeast of Goma, capital of troubled North Kivu province.

Five Congolese soldiers were killed in clashes with Rwandan troops on Wednesday, military and government officials said, as both sides traded blame for sparking the worst violence in months.

Machine gunfire broke out at dawn along the border after what the Congolese army said was the abduction of one of their soldiers by Rwandan troops who had crossed the border into the restive province of North Kivu.

Fighting involving heavy weapons flared again between Congolese soldiers and Rwandan troops on their volatile border on Wednesday, Congolese military and officials said, further straining relations between the rival neighbors.

Congolese regional commander Colonel Ephrem Ramazani said there had been "heavy weapon fire from both sides" as clashes erupted after several hours of calm.

One of Rwanda's most prominent opposition figures, Bernard Ntaganda, was freed on Wednesday after serving a four-year prison sentence for threatening state security and causing ethnic divisions, officials said.

Ntaganda, a lawyer and founder of the PS-Imberakuri opposition party, wanted to challenge President Paul Kagame in 2010 elections, but was arrested and jailed before the polls.

Human Rights Watch has reacted angrily to Rwandan allegations of bias in its reporting on the central African nation, saying it has been "misrepresented" and its staff "disparaged".

The statement from the group, released overnight on Monday, came after Rwanda's justice ministry accused the rights organisation of colluding with terrorists and signalled it may no longer be allowed to work in the country.

More than 100 armed Rwandan rebels from a group linked to the 1994 genocide in their homeland turned themselves in Friday in the eastern Democratic Republic of Congo, a decision welcomed by the U.N.

The rebels are members of the Democratic Forces for the Liberation of Rwanda (FDLR) which includes remnants of the militia that carried out the genocide of at least 800,000 ethnic Tutsis according to the world body and which is now based in DRC.

The Mali government signed a ceasefire deal with three rebel groups in the northern desert Friday, the African Union's negotiator announced, after the Tuareg and Arab insurgents captured the flashpoint town of Kidal.

The town is the cradle of Mali's separatist movement, which wants independence for a vast swathe of northern desert it calls "Azawad" and which has launched several rebellions since the 1960s.

Rwanda's President Paul Kagame went into private talks with France's Foreign Minister Laurent Fabius on Friday in the wings of a development forum in Gabon, a source close to the Gabonese presidency said.

The two men shook hands following weeks of newly strained ties two decades after the Rwandan genocide, according to an AFP journalist attending the third New York Forum Africa in Libreville.

Rwandan police have dismissed a rights report accusing the state of forced disappearances, saying there were "no missing" people but that they had arrested dozens as part of anti-terrorism operations.

The U.S.-based Human Rights Watch said Friday it had documented an increasing number of people who have been forcibly disappeared or have been reported missing since March.