Kidnappers in Somalia's northern Puntland region have freed two female aid workers from the Spanish branch of Medecins Sans Frontieres (MSF).

Abdisamad Yusuf Abwan, Puntland's trade minister, said on Wednesday: "The two MSF workers have been released by their abductors and they are now in a hotel in Bosasso."

Mercedes Garcia, a Spanish doctor, and Pilar Bouza, an Argentinian nurse, were seized by gunmen in Bosasso, a northern Somali port, on December 26 while driving to a hospital in the semi-autonomous region.

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

"We paid no ransom for their release."

Somali kidnappers generally do not harm their victims, instead treating them as an investment which can pay off in the form of ransom.

The Spanish branch of MSF withdrew its workers from southern Somalia on Tuesday after the abductions in Puntland, which had enjoyed a reputation for relative stability compared to the rest of the anarchic Horn of Africa nation.