Kenyan authorities say they suspect the Somali militant group Al Shabab is behind the kidnapping of two European aid workers Thursday, the third kidnapping of foreigners near the Kenya-Somali border in the past month.

Police spokesmen said gunmen seized the two aid workers from a huge Somali refugee complex in northern Kenya. So far, there are no reports of ransom or other demands from the gunmen.

Medical aid group Doctors Without Borders confirmed two of its staff, both Spanish, were abducted Thursday at the Dadaab refugee complex, from the recently-opened Ifo 3 camp.

The head of Doctors Without Borders' Spanish branch said the agency is in contact with all relevant authorities and doing everything possible to “ensure the swift and safe return” of the abducted women.

Kenyan authorities suspect the kidnappers may have tried to take the workers back to Somali territory. Dadaab is located about 100 kilometers from the Somali border. Authorities say heavy rains are hindering their search efforts.

A driver working with the aid workers was shot during the abduction and left behind. An official for Doctors Without Borders told VOA he is in stable condition.

A British tourist and a French woman were recently abducted at Kenyan resorts. Both of those women are being held captive in Somalia.

The Dadaab complex is home to more than 400,000 refugees, many of whom fled ongoing famine conditions and fighting in southern Somalia.