At least 214 young women and girls recently rescued from Islamist terrorist group Boko Haram in north-eastern Nigeria are pregnant, the UN Population Fund (UNFPA) said Monday.

Nigeria's army freed almost 7,000 women from various Boko Haram camps last week.

"Already, many of them are undergoing screening for various diseases, infections including HIV/AIDS," UNFPA Nigeria executive director Babatunde Oshotimehin told the Nigerian news agency.

Boko Haram kidnaps young girls to force them to convert to Islam, and presses them into marriage or keeps them as slaves.

None of those rescued have been identified as belonging to the more than 200 girls who were kidnapped from a school in the village of Chibok in April 2014.

Soldiers found an additional 260 women and children Monday on the outskirts of Chalawa village in Adamawa State who had escaped from the terrorists, army spokesman Chris Olukolade said in a statement.

Most of them come from the nearby town of Madagali and surrounding communities, according to the spokesman. Some had been abducted and later fled Boko Haram camps, while others had been on the run since the insurgents attacked Madagali several weeks ago.