Two Spanish doctors working for the medical charity organization Medecins Sans Frontieres (MSF) have reportedly been kidnapped by gunmen from a refugee camp near Kenya’s border with Somalia.

The doctors were reportedly seized while riding in a car.

Kenyan police told Reuters that both kidnap victims are women and that they believe al-Shabab, the Somali militant group linked to al-Qaeda, is responsible.

The physicians were helping to treat the estimated 450,000 Somali refugees who have flooded into the Dadaab camp, having escaped drought, famine and violence in the Horn of Africa.

The doctors’ driver, a Kenyan, was hurt in the attack and is now in the hospital, according to MSF.

In recent weeks, two foreign women (one from France, the other from Britain) have been kidnapped in the same area.

Kenyan police officials told BBC that they're tracking the kidnappers to the Somali border by road and by air.

Dadaab is only 50 miles from the Somali border.

Mike Wooldridge, a correspondent for BBC News at Dadaab, wrote: “Convoys of aid vehicles are a common sight on the dusty roads leading to and from the individual camps. But relief work of all kinds goes on daily across such a large area - in the hands of UN agencies and a host of non-governmental organizations - and it would be a near impossible task to seal the camps and prevent any possible infiltration by militant groups.”

Woolridge added: “This seizure of the MSF vehicle follows other vehicle hijackings. Aid officials say security is being immediately reviewed, with the likelihood that it will prompt more restrictive measures.

Moreover, despite the suspicions of Kenyan police, it isn't certain that al-Shabab is behind the kidnappings. While they control much of southern Somalia, they've historically denied kidnapping Westerners.