A disgruntled former employee has killed at least two foreign aid workers in the Somali capital, Mogadishu.

Officials say the shooting occurred Thursday at the offices of the aid group Doctors Without Borders (MSF). One person was killed on the spot and the other died later in the hospital.

The Doctors Without Borders issued a statement confirming the shooting accident on its compound in Mogadishu, but giving no other details. The group said it is doing everything to ensure the safety of its staff.

Some witnesses said the victims were foreign aid workers.

Some eyewitnesses said the gunman was a former Somali employee who had been dismissed from his job Wednesday.

“The gunman was fired from his job yesterday; he came to the compound today and managed to sneak through the patients, and kill the doctors. We were all scared when we heard the sound of the gunshots.”

Police say the gunman was taken into custody.

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

The shooting comes less than a week after three aid workers with the World Food Program were shot and killed in the central Hiran region of Somalia.

The impoverished Horn of Africa nation has not had a stable government since the 1991 coup. Militant Islamist group al-Shabab is fighting to take control of the capital Mogadishu and impose strict Sharia law in the country.