N’DJAMENA, Chad (AFP) — Two Chadian health workers are missing after they were abducted by an armed group who killed a colleague in the Lake Chad region, ALIMA, an international NGO active in the region, said Monday.

“A non-state armed group (NSAG) attacked health personnel” based at Fende 2, a locality in Lake Chad region some 200 kilometres (125 miles) northeast of the capital N’Djamena,” on Saturday, an ALIMA statement said, adding three of the workers managed to escape.

The NGO issued its statement after the UN coordinator in Chad had earlier announced the death and kidnapping of “humanitarian” workers from ALIMA-ALERTE SANTÉ.

ALERTE SANTÉ and ALIMA said in a statement they condemned the attack and others “perpetrated against the health workers who provide humanitarian support to Chadian populations.”

Since 2012, the Alliance for International Medical Action (ALIMA) and  Alerte-Santé have worked together on a medical and nutritional programme for infants in the region and N’Djamena, providing health services to displaced populations, according to the international NGO’s website.

Bordering Chad, Niger, Cameroon and Nigeria, Lake Chad is a vast expanse of water and swamps whose countless islets serve as hideouts for jihadist groups, such as Boko Haram and the Islamic State in West Africa (ISWAP) who spring regular attacks on the countries’ armies and civilians alike.

In June, the International Office for Migration (IOM) recorded more than 220,000 displaced people by attacks from armed groups in Lake Chad province.