Democratic Republic of Congo and Rwanda accused each other of firing rockets across their shared border on Friday, including a strike that killed two Congolese children, a spokesperson for the Congolese army said.

The alleged attacks are part of an escalating dispute between the Central African neighbours linked to a fresh offensive by the M23 rebel group that Congo accuses Rwanda of supporting.

The spokesman for the Congolese Army in the eastern North Kivu province said troops had been battling M23 rebels in a mountain area close to the border with Rwanda and Uganda, when five rockets fired from Rwanda landed in Congolese territory away from the area of fighting.

“We recorded two children killed and one seriously wounded and also a school which was thoroughly damaged,” spokesperson Guillaume Ndjike Kaiko said.

The Rwandan Defence Ministry meanwhile accused Congolese forces of firing two 122mm calibre rockets into Rwanda from the Bunagana area, where they were fighting M23 rebels.

“There were no casualties but the local population is terrified,” it said in a statement.

Kaiko denied the accusation and said Congolese forces had not been using rockets of that calibre in the area.

The dispute centres on Congo’s accusation that Rwanda is actively supporting M23, which has been waging its most sustained offensive in Congo’s eastern borderlands since capturing vast swathes of territory in 2012-2013.

Rwanda denies this and in turn accuses Congo of fighting alongside the FDLR, an armed group run by ethnic Hutus who fled Rwanda after taking part in the 1994 genocide.

It has accused Congolese forces of firing rockets across the border in two previous incidents in March and May.