Thirteen soldiers have been jailed for life after the discovery of mass graves in the north-eastern Ituri region of the Democratic Republic of Congo.
The mass graves were found in November last year
A military court found them guilty of killing about 30 civilians found buried in the graves in November last year.
This is one of the few times armed men have been punished for atrocities since the DR Congo conflict began in 1997.
Renewed fighting between government and rebels in the north-east is reported to have left more than 20 people dead.
The operational commander for North Kivu, Colonel Delphin Kayimbe, said 20 rebels and three government soldiers were killed in a remote part of the Virunga national park, near the border with Uganda.
The UN says more than 8,000 people were displaced by the fighting, which broke out when the army moved into an area previously occupied by rebels from the Mai Mai and Rwandan Hutu FDLR movements.
Of the 13 men sentenced over war crimes at the village of Bavi, four were tried in their absence. A captain was given a suspended sentence and a lieutenant was acquitted.
Those found guilty were also ordered to pay large fines to the victims' families.
They have five days to appeal.
The victims were believed to have disappeared in army operations against local militias early in 2006.
The three mass graves at Bavi - about 40kms (25 miles) from Bunia - were found in November last year after a tip-off from a soldier.
Witnesses said the military men "abducted the civilians and then forced them to work in local gold mines, to harvest food products and to transport goods", according to the AFP news agency.
The head of a local NGO Justice Plus told AFP the civilians were probably killed to cover up any traces of the abduction.
The soldiers who were tried came from the army's First Brigade - one of several made up of fighters from factions who fought in DR Congo's 1998-2003 war.
In a separate trial in Bunia, four members of the same unit were jailed for life for the murder of two UN military observers in 2003.
Two others were given jail terms of 10 and 20 years.
The murders took place in the mining community of Mongwalu, 70 kilometres north of Bunia on 12 May 2003 when the soldiers - then fighting with an Ituri militia - surrounded and "savagely killed" the two men, the UN said.
Following last year's landmark elections, DR Congo is supposed to be returning to normality after decades of conflict and mismanagement.