What you need to know:
DR Congo's government has regularly accused Rwanda of carrying out incursions into its territory and of backing armed groups there.
DR Congo soldiers fought M23 militiamen on several fronts in the troubled east of the country Wednesday, military and local officials said, with the government appearing to implicate Rwanda in the violent flare-up.
Fighting took place in the Kibumba area of eastern North Kivu province, about 20 kilometres (12 miles) north of the provincial capital Goma, said two military officers who declined to be named.
Another officer, who also requested anonymity, said a critical highway running to Goma had been cut off by the clashes. An AFP correspondent confirmed the highway was blocked.
Elsewhere in North Kivu -- which borders Rwanda and Uganda -- a local administrative official said soldiers had faced off against M23 fighters in Rutshuru territory, near the Ugandan border.
The M23 is one of more than 120 armed groups that roam eastern DR Congo, a legacy of regional wars more than two decades ago.
Also known as the March 23 Movement, it is a primarily Congolese Tutsi group that was crushed in 2013 after launching a rebellion.
But it resumed fighting this year, accusing the Congolese government of failing to respect a 2009 agreement under which its fighters were to be incorporated into the army.
Many in DR Congo suspect that Rwanda continues to back the M23, which Kigali denies.
The vast central African nation has regularly accused its smaller neighbour of conducting incursions into its territory, and of backing armed groups there.
The latest army clashes with the M23 follow fighting near Goma on Tuesday, which some also blamed on the militia.
The previous day, Rwanda had urged an investigation into an alleged rocket attack on its territory launched by Congolese armed forces.
On Wednesday, DR Congo's army called for a separate investigation into shelling fired "from the east to the west of the Goma-Rutshuru road", which it said had landed on Congolese territory.
The army statement did not mention Rwanda by name.
However, a senior military official told AFP on Tuesday that his forces had seized Rwandan army uniforms after clashes with militants in North Kivu that day.