A police station located in one of the biggest oil hubs of Iraq was attacked by a suicide bomber driving a truck on Saturday killing seven people and wounding other 13.

According to police officials, the site of the attack occurred in a neighborhood where many refinery workers and engineers live.

This incident in Beiji is the less deadly of the three suicide attacks that occurred in Iraq in 24 hours. It came a day after the attack of a key oil pipeline in the city.

A police official said that the attacker came near the police station with an explosives-laden truck, the Associated Press reports.

According to him, five policemen and two civilians were killed due to the explosion. The blast damaged houses that were in the proximity of the police station.

One man who lives nearby, Jassim Salih, said that the windows of his house were shattered and three members of his family were wounded.

Falih Salim, another witness, said that after hearing the explosion he rushed to the site of the explosion.

He said: "The scene was so horrible that I ran away."

Beiji is located about 155 miles north of Baghdad. It is home to the largest oil refinery of the country and is a key transfer point for crude oil which is exported. The area is guarded by 300 U.S. soldiers and 2,000 Iraqi troops, so little attacks occurred on the Kirkuk-Beiji pipeline cluster.

Due to the influx of U.S. troops which began in February, violence decreased in Iraq.

It is believed that since al-Qaeda lost so many sanctuaries, is know moving northward.

U.S. military commanders told on Wednesday U.S. Defense Secretary Robert Gates that there is a need for more soldiers to fight against al-Qaeda insurgents that were pushed out of the Baghdad region.