Firefighters spray water to a blasted oil tank in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region, on July 12, 2009. [Xinhua]

An oil tank explosion that occurred at a chemical plant in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region on Sunday morning, had no link to sabotage, a company official said.

The explosion happened around 9:50 AM at a refinery of the Urumqi Petrochemical Company, a subsidiary of the China National Petroleum Corporation, in the Midong district in northern Urumqi.

Police ruled out the possibility of intentional sabotage after on-the-spot investigation, said Liu Jiyuan, secretary of the Urumqi Petrochemical Company Committee of the Communist Party of China.

Patrolling workers of the plant found the No. 13 tank on fire at around 9:50 AM and immediately alerted company firefighting forces, said Liu.

The fire triggered by the blast was extinguished at 10:30 AM.

No casualties were reported.

The exact cause of the accident is being investigated.