Bomb Rocks Pakistan's Largest City

Nov. 11: Pakistani security officials and media gather at the site of a bomb explosion in Karachi, Pakistan. (AP)

KARACHI, Pakistan -- Militants attacked a police compound in the heart of Pakistan's largest city on Thursday with a hail of gunfire and a massive car bomb, leveling the building and killing at least 15 people, authorities and witnesses said.

The gang of around six gunmen managed to penetrate a high-security area of Karachi that is home to the U.S Consulate, two luxury hotels and the offices of regional leaders. While no stranger to extremist violence, Karachi has not witnessed this kind of organized assault in recent years.

It was the first major attack against a government target outside the northwestern tribal regions for several months, showing the reach of Islamist militants seeking to overthrow the U.S.-allied government despite efforts to crack down on them over the last three years.

The gunmen first opened fire on the offices of the Crime Investigation Department before detonating a huge car bomb, said Sindh Home Minister Zulfiqar Mirza. The building has a detention facility that was believed to be holding criminals, and possibly militants.

The CID takes the lead in hunting down terrorists in Karachi. Earlier this week, the agency arrested six members of Lashkar-e-Jhangvi, an Al Qaeda linked group blamed for several high profile attacks in recent years. The suspects were presented before a court earlier Thursday.

The blast could be heard several miles away in the city of 14 million people. It destroyed much of the multistory police building, damaged nearby houses and left a 10-feet wide crater in the road. The U.S. Consulate was around a mile away, but was undamaged.

"We heard different kinds of firing for several minutes and then a deafening explosion," said Ali Hussain, who was covered in dust. "The roof of our house collapsed."

Bloodied and dazed victims were taken to ambulances, some of them children pulled from the debris. Security officers searching through mangled bricks and iron looking for survivors late into the night.

Sindh government spokeswoman Sharmila Farooqi said 15 people, including five police officers, were killed. About 100 people were injured.

Islamist militants with bases in the northwest close to Afghanistan began targeting the state in earnest in 2007.

Many thousands of people, most of them civilians, have been killed in suicide attacks against government, police and Western targets, as well religious minorities.

The government has declared war on the militants, and the army has moved into several areas in the northwest. But the insurgents have proved to be remarkably resilient, drawing on networks across the country inspired or allied to Al Qaeda, which is itself headquartered in the northwest.

While militant groups often claim responsibility for the attacks, some Muslim political parties and leaders, angry at the U.S. role in Afghanistan, allege American involvement, hampering the fight.