Bomb blast kills three in Pakistan's Lahore: Police

A bomb exploded close to the police headquarters in the eastern Pakistani city of Lahore on Tuesday, killing three people in a rare attack in the city that is Prime Minister Nawaz Sharif's powerbase.

Lahore, Pakistan's second largest city which is seen as relatively liberal, has largely escaped the worst of the Islamist violence that has engulfed the country in the last decade.

Tuesday's blast hit just metres from an entrance to the police headquarters in the heart of the city, sending a column of black smoke rising above buildings.

"According to initial reports it was a car bomb but we are still determining the exact nature of the blast," senior police official Haider Ashraf told AFP.

"At least three people have been killed in the explosion."

Television footage showed several vehicles on fire after the explosion, which left the street littered with broken glass and debris from nearby buildings.

The blast comes just days after 22 people were killed in a gun and suicide attack on a Shiite mosque in the northwestern city of Peshawar.

The Tehreek-e-Taliban Pakistan (TTP) claimed responsibility for Friday's attack in Peshawar, saying it was revenge for a militant known as Doctor Usman, who was hanged in December.

The country has stepped up its fight against militants since Taliban gunmen massacred more than 150 people, most of them children, at a school in Peshawar in December.

Following the massacre, Sharif ended a six-year moratorium on the death penalty and Doctor Usman, also known as Aqil, was one of the first to go to the gallows.

He was convicted for an attack on the army headquarters in Rawalpindi in 2009 and was arrested after being injured.

In claiming Friday's attack, the TTP vowed to continue their campaign of violence.

Since June last year the army has been waging a major campaign against strongholds of TTP and other militants in the North Waziristan tribal area, which lies close to Peshawar.

The military has heralded the success of the operation, which it says has killed more than 2,000 militants, though the precise number and identity of those killed cannot be verified independently.

Lahore has remained relatively peaceful during the TTP's seven-year campaign of bomb and gun attacks, which has left thousands of civilians dead.

But last October a suicide bomber killed at least 55 people at Wagah, Pakistan's main land border with India, close to Lahore.