World Bulletin / News Desk

Motorcycle gunmen on Wednesday shot dead seven policemen guarding a polio vaccination team in Pakistan's southern port city Karachi, officials said, a brazen attack in the country's economic hub.

Feroz Shah, a senior police official, told AFP that eight gunmen carried out the killings in two separate attacks in the city's western Orangi Town neighbourhood.

"The gunmen first opened fire on three policemen in the streets of Orangi Town, killing them all," he said, adding: "Later they shot dead four policemen, who were sitting in a police mobile van" a few streets away.

Abdul Kareem, an official in Abbasi Shaheed Hospital where the bodies were taken, also confirmed the casualties.

The polio workers, who were unharmed in the attack, were on the third day of an immunisation drive.

Provincial home minister Sohail Anwar Siyal told the private Dunya TV channel: "The policemen sacrificed their lives to protect the polio workers."

A faction of the Pakistani Taliban, Jamaat-ul-Ahrar late Wednesday claimed responsibility for the attack.

"We claim responsibility for this attack on police in Karachi, this was a part of ongoing attacks on police and law enforcement agencies," said group spokesman Ehsanullah Ehsan in a statement sent to AFP by email.

Armed outfits including the Pakistani Taliban say the polio vaccination drive is a front for espionage or a conspiracy to sterilise Muslims.

Police and rangers later cordoned off the areas where their colleagues had been killed.

The interior of the police van was heavily soaked with blood, with an officer's cap lying on the front seat.

Speaking to the media, provincial police chief Allah Dino Khawaja announced a $50,000 reward for the arrest of the gunmen, as well as $20,000 compensation to each of the victims' families.