Gunmen have killed a United Nations World Food Program worker in Somalia - the second WFP staff member killed there this week.

Agency spokesman Peter Smerdon says unidentified gunmen shot and killed the aid worker Thursday as his team distributed food in the Daynile district, northwest of the capital, Mogadishu.

Smerdon says the attackers drove off in a WFP vehicle afterward.

On Tuesday, masked gunmen shot and killed another WFP food monitor at a school in southwestern Somalia.

Smerdon tells VOA it is not clear whether the killings are connected.

Earlier Thursday, a French medical charity said two of its workers who were kidnapped in Somalia in September have been freed.

Doctors of the World (Medecins du Monde) said Japanese national Keiko Akahane and Dutch citizen Wilhem Sools were released Wednesday. It did not give information about the circumstances of their release.

The two were kidnapped on September 22 near the Ethiopian-Somali border. Doctors of the World provides aid to victims of the drought gripping Ethiopia's Ogaden (or Somali) region.

Somalia is considered one of the most dangerous places in the world for aid agencies to operate, but it is also one of the countries where their assistance is most needed.

The World Food Program says more than three million Somalis - nearly half the country's population - are in need of humanitarian aid.

Some information for this report was provided by AFP and Reuters.