Updated

A Somali official says pirates who seized an oil tanker have opened fire on naval troops from the semiautonomous state of Puntland, sparking clashes between the two sides.

Ali Shire Mohamud, the commissioner of Alula district where the ship is being held, says clashes started after naval forces tried to stop a boat carrying reinforcement pirates to the ship.

Puntland dispatched naval forces to the area after the pirates seized the ship on Monday.

Mohamud declined to give further details.

The European Union anti-piracy operation in the region says 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.