Updated

More than 80 children, some as young as eight years old, have been rescued from an armed group in the southeastern Democratic Republic of Congo and are being reunited with their families, the UN said Friday.

The 82 youngsters, including 13 girls, had been recruited by force by the Mai Mai Bakata-Katanga militia who are active in the restive province of Katanga, the UN peacekeeping mission in DR Congo (MONUSCO) said in a statement.

The youngsters, aged eight to 17, were separated from the militia on August 11 and 15 thanks to the joint effort of local child protection agencies in the province, MONUSCO added. The children had reportedly been recruited over the past six months.

Forty of the rescued children "were immediately reunited with their families, while the remaining are receiving interim care pending reunification," the statement read.

MONUSCO head Martin Kobler said the UN was "extremely concerned" about ongoing reports of active recruitment by armed groups in eastern DR Congo.

"Children face unacceptable risks when they are recruited for military purposes," he said.

"The recruitment of children, particularly those under 15 years of age, could constitute a war crime and those responsible must be held to account."

MONUSCO estimates that 163 children, including 22 girls, have been separated from Mai Mai Bakata-Katanga fighters since the beginning of the year.

Katanga, the home province of President Joseph Kabila, is regularly engulfed by secessionist unrest dating back to 1960 when the mining province announced it was seceding from the rest of the nation, triggering a long series of wars and rebellions.

Katanga province is the richest part of the country, with various mineral resources including copper, which is the mainstay of foreign exports.

Tensions have been rising in recent months, with the Bakata-Katanga complaining about what it sees as the unequal distribution of wealth between the poorer northern parts of the province and the richer southern areas, where foreign firms operate.

In March, clashes erupted between army troops and the militia group, including child fighters, in the provincial capital of Lubumbashi, leaving 23 dead.