"UNICEF which condemns the abduction, is concerned that the abducted children are being inhumanely treated and is calling for them to be released immediately," it said.
The UN agency said that 11 boys and two girls were believed to have been kidnapped by an armed group during an attack on a village in North Kivu province.
On January 22, suspected Allied Democratic Forces (ADF) militants killed at least 23 people during an attack on the village of Makugwe, and kidnapped several people, sources previously told AFP.
The ADF is one of the deadliest armed groups in eastern DRC, a volatile region that has been plagued by violence for decades.
The militia -- which the Islamic State group claims as its central African affiliate -- has been accused of slaughtering thousands of Congolese civilians and carrying out bomb attacks in Uganda.
In 2021, the United States officially linked the ADF to IS and added it to its list of foreign terrorist organizations.
On January 15, suspected ADF operatives also detonated a bomb in a church in North Kivu, killing at least 14 people and injuring another 63.