Two foreign aid workers who were kidnapped last week in Somalia were released Tuesday, a diplomat said.

The abducted women — a doctor from Spain and a nurse from Argentina — were seized Dec. 26 in Puntland, a semi-autonomous region in northeastern Somalia.

"We are happy the two are released," said Nicolas Martin Cinto, the Spanish ambassador to Kenya.

Puntland often serves as a staging area for human traffickers running boats into Yemen, and piracy has been rampant off its coast. In recent months, however, the U.S. Navy has led international patrols to combat piracy in the region, cutting down on attacks on merchant ships and vessels carrying aid.

On Dec. 24, French journalist Gwen Le Gouil was released after eight days in captivity in Puntland. Le Gouil's kidnappers had demanded about $70,000 in ransom; police said it was not paid.

Puntland is about 930 miles north of the Somali capital, Mogadishu, where an Islamic insurgency has killed thousands of people this year. The United Nations says Somalia is facing Africa's worst humanitarian crisis.