Suicide blast kills two at police HQ in Nigerian city

A suicide blast at the police headquarters in Nigeria's restive city of Maiduguri Friday killed at least two policemen and wounded six other people, authorities and witnesses said.

It was the latest violence to hit the tense northeastern city that has been at the center of Islamist group Boko Haram's insurgency, which has killed more than 1,000 people since mid-2009.

"A suicide bomber tried to force his way into the police headquarters... However, he rammed the car into sand-filled drums outside headquarters and his car exploded," a police source said.

"We have some casualties, but we're trying to sort out the extent of fatalities and the injured."

A witness reported seeing the bodies of two policemen.

Another witness said he saw five wounded policemen and what appeared to be an injured pregnant woman being taken away to hospital.

A hospital source confirmed that the bodies of two policemen had been brought in as well as the six wounded mentioned by the witness.

"At the moment, we have two bodies of policemen brought to the hospital from the suicide attack at the police headquarters," the nurse said on condition of anonymity.

"Six people, comprising five policemen and a pregnant woman, were brought with injuries from the explosion."

The state police commissioner confirmed the explosion, but declined to provide further details, saying he was at the hospital where wounded had been taken.

The bloody attack was the latest to hit Maiduguri, the city where Boko Haram's mosque and headquarters were located until they were destroyed in a 2009 military assault.

In August, a suicide bomber sought to attack the same building -- the police headquarters for Borno state -- but he was shot dead by authorities.

Security has been extremely tight in the area in recent months, including checkpoints and road traffic restrictions. A special military task force has put hard-hit areas of the city in lockdown.

The city has been hit by repeated bombings and shootings, often targeting security forces. Thousands of residents have fled the spiraling violence.

On Tuesday, Nigerian soldiers killed at least 16 militants when they moved into an area of Maiduguri where Boko Haram members were believed to be hiding. Gunfire and blasts rocked the area for several hours.

Boko Haram's attacks have grown increasingly sophisticated and have affected a wider area, spreading from their base in the northeast across the wider north and down to the capital Abuja, in the center of the country.

It claimed responsibility for a suicide bombing of U.N. headquarters in Abuja in August which killed at least 25 people as well as a suicide attack on the Abuja office of one of the country's most prominent newspapers.

The group has continually widened its targets, which have included security forces, churches and police headquarters in the capital.

Nigeria, Africa's most populous nation and largest oil producer, is roughly divided between a mainly Muslim north and predominantly Christian south.