Heavy exchange of fire between the attackers and police was reported from outside the building Local media said the attackers stormed into the police facility before trying to fortify themselves KARACHI: A group of armed men launched an attack on Karachi police headquarters on Friday, reported the local media, adding they had forced their way into the building as heavy exchange of fire was heard between the attackers and the police. A government spokesman said at least four people had been killed in the attack. “Four people were killed in the attack, including two policemen, one ranger, and one sanitary worker,” Sindh government spokesman Murtaza Wahab Siddiqui said, adding 14 others were wounded. “The operation has concluded with the killing of all three terrorists,” he said. Security forces retook the building after several hours, the spokesman said. Police commandoes and a bomb disposal squad entered the building and a security sweep was under way. Pakistan has witnessed a surge in militant violence in recent months after a proscribed network, Tehreek-e-Taliban Pakistan (TTP), unilaterally called off a cease-fire with the government last November. A TTP spokesman claimed responsibility for the attack. TTP fighters have launched similar attacks in the past in which they temporarily fortified themselves in government facilities while fighting the police and other security agencies. The attack comes just weeks after a bomb blast at a police mosque in the country"s northwest killed over 80 officers, and officials said late Friday that security would be stepped up in the capital Islamabad. “Heavy exchange of fire between attackers and police can be heard outside the police headquarters in Karachi,” said Geo News television. One of the correspondents of the channel said the attackers were thought to have entered the building where they were fighting with police personnel. Prime Minister Shehbaz Sharif vowed Friday to stamp out the violence. “Pakistan will not only uproot terrorism, but will kill the terrorists by bringing them to justice,” he tweeted. “This great nation is determined to end this evil forever.” * This article originally appeared on Arab News Pakistan edition, click here to read it. * With AFP