Heavy fighting erupted overnight in eastern Democratic Republic of Congo when fighters from the M23 rebel group attacked army positions near the border with Uganda and Rwanda, a local official and a witness said on Monday.
"I confirm the attack since last night on our positions," said Muhindo Luanzo, assistant to the military administrator of the eastern town of Rutshuru.
"(The village of) Runyoni is also besieged by the enemy but our troops are already deployed to respond and chase the enemy."
The clashes began at around 0100 local time (2300 GMT) near the villages of Tshanzu and Runyoni, around 50 km (31 miles) north-east of the provincial capital Goma, a witness in Runyoni said.
"We don't know who controls the area, but it looks like it's a serious attack," the witness told Reuters.
"This time it was more intense than all the previous times."
The M23 had briefly seized those two strategic villages in a similar overnight attack in November.
A spokesman for the M23 could not immediately be reached for comment.
The fighting comes three days after the group, which seized large swathes of territory during an insurrection in 2012 and 2013, accused the army of waging war against it.
Tshanzu and Runyoni were the last redoubts of the M23 before its fighters were chased out by Congolese and United Nations forces into Uganda and Rwanda in 2013.
There have since been regional efforts to have the group demobilise. But its leaders have complained about the slow pace of implementation of a peace accord.
"Our organisation, the M23, which has been able to patiently wait nine years for the implementation of the peace process, deplores this dreadful option of violence," said M23 spokesman Willy Ngoma in a statement last week.
U.N. investigators have previously accused Rwanda and Uganda of supporting the M23. Both countries, which intervened militarily in Congo during two regional wars two decades ago, deny supporting the group.
(Reporting by Djaffar Al Katanty; Writing by Hereward Holland; Editing by Sofia Christensen and Gareth Jones)
