Al Qaeda in the Islamic Maghreb (AQIM), the North African offshoot of the militant group, took a Swiss nun hostage and in exchange, demanded the release of its members imprisoned by the Malian government, the SITE Intelligence Group said Tuesday. Beatrice Stockly, who was abducted about three weeks ago in northern Mali, appeared in a video released by the group, according to the monitor.

In the video, the militants put forth conditions for the nun’s release. Stockly, who was previously kidnapped for nine days by another militant group Ansar al Dine in Mali in 2012, appeared in a veil in the eight-minute video and stated that the footage was filmed on Jan. 19, Reuters reported citing the SITE group.

"We, al Qaeda in the Islamic Maghreb, the Sahara region, declare our responsibility for the kidnapping of this Christianizing kaffir Beatrice Stockly, who by her work, drove out many from the fold of Islam by seducing them with crumbs of this worldly life," an English-speaking militant reportedly said, in the video.

Al Qaeda members also demanded the release of Ahmad Al Faqi Al Mahdi, an alleged member of Ansar al Dine, a Tuareg Islamic extremist group in North Africa. Al Mahdi is in custody of the International Criminal Court for the war crime of attacking religious and historical buildings in Timbuktu, Mali.

Earlier this month, the Swiss foreign ministry said it organized a task force for Stockly’s release. According to the ministry, Swiss officials had advised the nun to avoid returning to Mali after the 2012 abduction, CNN reported. Stockly lived in Timbuktu for several years and was said to be the last Westerner living in the city, which she refused to leave after Ansar al Dine rebels took its control on April 1, 2012, according to Agence France-Presse.

Mali, a Muslim-majority country, was considered a success story in terms of democracy in Africa and the West’s counterterrorism efforts. However, political turmoil in northern Mali between ethnic Tuareg rebels and the government in 2012 resulted in a military coup, deteriorating security in the country and allowing militant groups to operate freely in the north.