Somali forces who have surrounded pirates holding hostages taken from an Indian ship secured the surrender of 10 members of the band on Tuesday and enlisted the parents of the other three to persuade them to give up, officials said.
Regional security forces rescued the Indian cargo dhow Al Kausar on Monday but pirates who seized it earlier this month escaped beforehand with nine crew members as bargaining chips to try to force the release of pirates jailed in India.
Hirsi Yusuf Barre, mayor of Galkayo in Somalia's Galmudug state, said 10 of the pirates surrendered after they were surrounded, leaving just three holding the nine dhow crew.
Apart from denying the pirates food and water, security forces had brought the parents of the three pirates to the scene to persuade their sons to give up, Barre said.
"The remaining three pirates will be taken out by their parents in the coming hours. We shall rescue the nine crew soon and they will rejoin their two colleagues on the ship," he said.
Two of the dhow crew were rescued on Monday after being left in a car that the pirates had to abandon after a chase.
The hijacking of the Al Kausar was part of a sudden string of attacks by Somali pirates after years without a reported incident. Attacks peaked with 237 in 2012 but then declined steeply after ship owners improved security measures and international naval forces stepped up patrols.
This month has seen a new rash of attacks, with two ships captured and a third rescued by Indian and Chinese forces after the crew radioed for help and locked themselves in a safe room.
Residents of Somalia's Indian Ocean coastline say piracy has resumed after local officials issued permits for foreign fishing vessels to fish in Somali waters. The foreign fishermen they say, have cut nets belonging to locals and run down small boats.