Somali pirates who seized an oil tanker have opened fire on naval troops from the semi-autonomous state of Puntland, sparking clashes between the two sides, an official said.
Clashes started after naval forces tried to stop a boat carrying reinforcement pirates to the ship, said Ali Shire Mohamud, the commissioner of Alula district where the vessel is being held.
Puntland dispatched naval forces to the area after the pirates seized the ship on Monday.
The European Union anti-piracy operation in the region said the pirates are holding the crew captive and demanding a ransom.
The hijacking on Monday was the first such seizure of a large commercial vessel off Somalia since 2012.
International anti-piracy patrols on the crucial trade route had calmed such attacks.