BUJUMBURA -- A second mass grave said to contain at least five corpses killed during protests against President Nkurunziza's third term since April was discovered Friday at Mutakura in the Burundian capital Bujumbura, authorities have said.

"We were informed by citizens that there were a mass grave at Mutakura at the 13th Avenue where more than five persons who supported the candidature of the Burundian president had been buried," said Eddy Hakizimana, administrator of Ntahangwa urban commune.

According to him, one of the victims had been already unearthed and activities continued for the remaining corpses buried in the same compound.

"It is one of the insurgents who surrendered to security forces who showed us the mass grave. The corpse that has been exhumed has not however been identified yet," said Hakizimana.

The ex-insurgent indicated that the unearthed man was killed in January, adding that he witnessed the victim's murder.

"I was a rebel fighter working for the Restoration of a Rule of Law (RED-Tabara) rebel group and I was the coordinator in charge of Nyakabiga and Jabe (in the capital Bujumbura). I had gone to Mutakura when the victim was killed," said Clovis Kwizera, a former insurgent.

On Feb. 29, another mass grave said to contain at least 30 corpses of President Nkurunziza's supporters was discovered in the same Mutakura neighborhood that was active during protests against Burundian President Pierre Nkurunziza's third term bid since April 2015.

Burundi is facing a political turmoil that broke out since April 2015 following the announcement by Burundian President Pierre Nkurunziza that he would be seeking a third term.

His candidature, which was opposed by the opposition and civil society groups, resulted in a wave of protests, violence and even a failed coup on May 13, 2015.

Over 400 persons are reported to have been killed since then while some 240,000 citizens sought exile in neighboring countries.

Xinhua