Fighting has resumed between the army and rebels in the Democratic Republic of Congo, just days after peace talks were suspended.
Clashes took place about 25km to the north of the strategic eastern city of Goma on Friday, rebel spokesman Vianney Kazarama told the AFP news agency.
Both sides accused each other of starting the fresh outbreak of fighting.
"The army attacked our positions at 4am," Kazarama said.
But Olivier Hamuli, spokesman for the army in the flashpoint province of North Kivu, said: "They attacked us."
A source from the UN peacekeeping mission in the country, MONUSCO, said the rebels carried out the first attack.
"Fighting is ongoing. These are not skirmishes," said the source, who did not wish to be named.
There were no immediate reports of casualties.
On Monday, both sides announced a halt to peace talks taking place in the Ugandan capital, Kampala, despite UN pressure to end the year-and-a-half-old rebellion ravaging DR Congo's mineral-rich but volatile east.
According to the Congolese government, the talks were suspended due to disagreement over the extent of an amnesty for the army mutineers and their reintegration into the national army.
Backed by the international community, DR Congo's government is refusing to give amnesty to about 80 leaders of the M23 rebels and to enlist these men into military ranks.
Members of the M23 group are mainly Tutsi fighters from an earlier rebellion who were incorporated into the army in 2009 and then mutinied in 2012.
They took control of the provincial capital, Goma, for more than a week late last year before withdrawing under international pressure.
Kinshasa has long accused Rwanda of pulling the strings behind the rebellion and UN experts have even said that the M23's "de facto chain of command" was topped by Rwanda's defence minister.
Kigali has vehemently denied accusations that it is arming, financing the rebels - and even supporting them with its own forces.