Karachi: Pakistani investigators Friday accused Taliban and al Qaeda-linked bombers of attacking police in Karachi, stoking fears that Islamist networks are expanding their fight in the country`s economic capital.
Gunmen rode up to the Criminal Investigations Department (CID), used to detain terror suspects, on Thursday evening, exchanged fire with police and detonated a truck packed with explosives.
The attack killed up to 18 people and severely damaged the building in Karachi`s most fortified downtown area, near government buildings, the US Consulate, five-star hotels frequented by Westerners and high-rise company offices.
Tehreek-e-Taliban Pakistan (TTP) swiftly claimed responsibility, with spokesman Azam Tariq telling a news agency from an undisclosed location that the attack was to avenge "the arrest and torture" of his comrades.
A day earlier, Karachi police said activists from Lashkar-i-Jhangvi, a group linked to al Qaeda and notorious for bombing Shiite Muslims, had been arrested. Officials on Friday said TTP members had also been rounded up in recent weeks.
"We detained at least 10 suspects from the bomb site and the nearby impoverished neighbourhoods," one security official told a news agency on condition of anonymity.
"We think they have links with TTP and Lashkar-i-Jhangvi.
"We have arrested quite a large number of suspects in the last few months from Karachi and it shows that these groups have penetrated into the city. It seems as though these people have gained strength in Karachi."
The teeming city, with a population of 16 million, is politically tense and steeped in rivalries between the Urdu-speaking majority and an influx of ethnic Pashtuns from the northwest, which has been hit by Taliban insurgency.
But while outbreaks of political violence have killed more than 150 people this year and extremists have targeted Shiite and Sufi religious gatherings, attacks on government security forces in Karachi have been rare.
The significance is not to be underestimated. Karachi is Pakistan`s economic hub, home to its stock exchange and lifeline for a depressed economy wilting under inflation and stagnating foreign investment.
It has further attracted attention from Islamist militants as the Arabian Sea port where NATO supplies dock to be trucked overland to support the more than 150,000 US-led troops fighting the Taliban in Afghanistan.
Pakistani analysts said militant organisations had regrouped and were capable of dragging government forces into urban guerrilla warfare.
"The message is very clear. Law enforcement agencies arrested members of LJ and TTP and they conveyed that they have enough power to respond. They are preparing to fight the government," said security analyst Hasan Askari.
"For the Pakistani state, it is going to be kind of urban guerrilla warfare if they want to eliminate these groups.
"They`re not in a position to overwhelm the state, but they are capable of sudden attacks and causing instability."
The United States frequently calls on Pakistan to step up the fight against extremists that it says are fuelling the war in Afghanistan.
Pakistan flatly denies US suggestions it is not doing enough to tackle Taliban and al Qaeda-linked militants who have carved out strongholds in the northwest and last year inched closer to the capital Islamabad.
According to Pakistani military statistics, 2,421 army and paramilitary soldiers were killed in fighting from 2002 until April this year.
Bombings across the country have killed more than 3,800 people since government troops stormed a radical mosque in Islamabad three years ago.
A Pakistani intelligence official told a news agency there were two Jhangvi factions in Karachi, one allied to TTP that carries out bomb attacks and kidnappings, and another focused on killing Shiites.
"It seems as though TTP and its allied LJ group were involved in yesterday`s attack. They have been preparing suicide bombers," the official said.
"Some important security buildings in Karachi were their targets and this CID office had been receiving threats for quite some time."
He said that 13 Jhangvi and TTP suspects arrested in recent weeks had been held at the CID building, but that they were moved shortly before the attack, which he said had been weeks in the planning.