International aid group Doctors Without Borders says it is closing its two largest medical centers in Somalia's capital after of two of its workers were killed last month.

The group said Thursday it is shutting down the 120-bed facilities in Mogadishu's Hodan district, where it has been treating malnutrition, measles and cholera.

The director of Doctors Without Borders, Christopher Stokes, said it is hard to stop those services in an area where the group is saving lives, but that the “brutal assassination” of its workers makes it impossible to continue.

A Belgian emergency coordinator and an Indonesian doctor were killed December 29 by a former local employee of the aid group.

Mogadishu is one of the world's most dangerous places for foreign workers.

Somalia has not had a stable government since a 1991 coup. The militant Islamist group al-Shabab is fighting to take control of Mogadishu and impost strict Sharia law in the impoverished country.