A string of kidnappings and targeted killings of aid workers in Somalia in recent weeks has prompted some international and local agencies to suspend operations in Mogadishu and in other parts of the south.  As VOA Correspondent Alisha Ryu reports from our East Africa Bureau in Nairobi, there is confusion about who may be responsible for the violence.   

The head of a Somali group affiliated with the German charity Bread for the World says the organization has suspended operations in Somalia, following Friday's fatal shooting death of its deputy director at his home in Mogadishu.

In a separate attack earlier that day, the head of a local aid organization, SORDA, was critically wounded by gunmen, as he distributed food to internally displaced people south of the capital.  Also on Friday, an aid worker was reportedly shot to death in a town in central Somalia as he left his house to attend services at a nearby mosque.

Eight days ago, gunmen shot and killed the director of the U.N. Development Program in Mogadishu.  Leaflets threatening local aid workers with death if they continue working have been found in Mogadishu and elsewhere.   

On Sunday, UNDP staff withdrew from the town of Baidoa, which hosts Somalia's transitional parliament, amid rising security concerns for its employees in the country.

The director of Mogadishu's Medina Hospital, Dr. Mohamed Yusuf, says even veteran humanitarian workers who have survived 17 years of lawlessness and violence in Somalia, acknowledge the current security situation is the worst they have faced.  

"Yes, they are afraid," he said.  "Some of our colleagues, they got some threats.  But you know, the situation is not so easy to talk about."

Suspicion for the attacks has fallen on a hardline Islamist opposition faction based in Eritrea, which rejected a peace deal signed last month in Djibouti between the Ethiopia-backed government and a more moderate opposition faction.  The hardline Islamists, along with a militant Somali group called the Shabab, have vowed to continue fighting until all Ethiopian troops leave Somalia.

Ethiopia's military intervened in Somalia in late 2006 to remove Islamists from power and to install the country's secular government in its place.  That move sparked a bloody, Islamist-led insurgency, which has left thousands dead and more than one million people displaced.  

Through a combination of war, drought, and food shortages, the United Nations says three million people in Somalia are facing a catastrophic humanitarian crisis throughout the country. 

International and local humanitarian organizations have declined to speak publicly about who may be responsible for the attacks.  But one western aid worker, speaking on the condition of anonymity, tells VOA that there is no evidence to suggest that Islamist insurgents are involved.