By Ahmed Elumami

TRIPOLI, May 25 (Reuters) - A power station in a central Libyan city has shut down from lack of fuel, after war planes belonging to the country's official government bombed a tanker delivering supplies, officials of the state-owned power company said on Monday.

Air force commander Saqer al-Jouroshi said jets attacked the Libyan-registered tanker Anwaar Afriqyaying outside the port of Sirte on Sunday because it had been discharging weapons. But state oil firm NOC said the tanker had been bringing 30,000 tonnes of fuel to Sirte's power station.

A Reuters reporter filmed the tanker and visited the vicinity of the power station and saw no evidence of weapons being brought onshore. The ship had been anchored next to a fuel feeding installation.

"The power plant of Sirte has shut down due to a lack of gasoline operating the plant," said Ashraf al-Marimi, a spokesman for the state power firm, GECOL, in Tripoli.

NOC, also based in Tripoli, said the attack would make it difficult to convince foreign shippers to dock at Libyan ports and would also increase insurance costs for cargoes.

"This attack targeted directly ... the property of the Libyan people," NOC said in statement. NOC owns the tanker that was attacked.

Shutting down the power station would worsen power cuts across Libya, it added.

The air strike is the third against oil tankers confirmed by the internationally recognised government based in eastern Libya. The attacks are part of a conflict between competing governments allied to armed factions, which are fighting for control four years after Muammar Gaddafi was ousted.

The power plant on the western outskirts of Sirte is controlled by forces loyal to the rival government in Tripoli. The rest of Sirte has fallen into the hands of Islamic State, who are exploiting the near-chaos in Libya.

The eastern government had already attacked a Greek-operated tanker docking at Derna in January, killing two seamen, and again accused the shipper of sending weapons. NOC had said the tanker was only carrying heavy fuel oil for a power plant.

Two weeks ago, forces loyal to the official government shelled a Turkish ship off the Libyan coast after it was warned not to approach. One crew member was killed in what Turkey described as a "contemptible attack".

(Reporting by Ahmed Elumami and Ulf Laessing; Editing by Larry King) ((ulf.laessing@thomsonreuters.com; follow me on twitter @ulflaessing; Tripoli newsroom; Reuters Messaging: ulf.laessing.reuters.com@reuters.net))

Keywords: LIBYA SECURITY/