NAIROBI, Kenya — Gunmen abducted two workers for the medical charity Medecins Sans Frontieres from the Dadaab refugee complex in Kenya Thursday, agency staff told CNN.

The Spanish women were part of the international staff working for MSF, also known by its English name, Doctors Without Borders, an MSF staff member said.

The attack took place in a new camp known as Ifo 3, the staffer said. He said the two women as well as their pickup truck were missing. The driver, shot in the neck, was in stable condition at a hospital.

A Spanish Foreign Ministry spokesman in Madrid confirmed the kidnapping. He said the women worked in logistics for the agency, but would not provide their identities or further details about the incident. He said their families have been informed.

The spokesman said the Spanish ambassador to Kenya and other foreign ministry officials were working to secure their release.

Dadaab, about 80 kilometers from the Somali border, is the largest refugee complex in the world. It houses thousands of people who have fled war and famine in the Horn of Africa.

United Nations staff and international aid workers often travel with armed Kenyan police escorts from their bases to the various camps. They are not allowed, under their regulations, to travel on their own.

However, MSF usually operates without a security escort. The medical humanitarian organization delivers emergency aid to people affected by war, epidemics and disasters.

A Kenyan driver from Care International was abducted in September in a nearby camp and is still missing.

Aid workers have long worried about security in Dadaab, particularly since the refugee processing center at the border has been closed by the Kenyan government for several years.

“Virtually anybody could be arriving in Dadaab,” a U.N. official said.