A suicide bomber in a pick-up truck filled with explosives attacked a police building in north-west Pakistan today, killing five police officers and wounding at least 30 other people in the latest round of bloodshed to hit the country since the US raid which killed Osama bin Laden.
The Pakistani Taliban claimed responsibility for the early- morning strike in Peshawar, and promised more attacks as they and other al-Qa'ida-affiliated groups seek to avenge the leader's death.
Already this month, the Pakistani Taliban has claimed three other revenge attacks, including a deadly 18-hour siege of a naval base.
The bomber's target today appeared to be the police's criminal investigation department, but the building was also an army base and several military facilities are also nearby, said Liaquat Ali Khan, a senior police official in Peshawar.
Investigators with the police counter-terrorism unit were stationed at the centre, said Fayaz Khan Toru, the top police official in north-western Khyber-Pakhtunkhwa province.
Police officer Mohammad Zahid was in the basement of the building when the bomb went off.
"I felt like the sky fell on me," he said in hospital, where he was being treated for multiple injuries. "The explosion jammed the door of my room in the basement, but there was a small hole in the wall so I crawled through that. When I got outside, there was lots of dust and smoke."
At least five police officers died, and 30 people were wounded, police official Jalal Khan said. Military forces quickly sealed off much of the area as machines were brought in to sift through the huge piles of rubble left at the site of what was once a multistorey building.
The Pakistani Taliban, while hostile to the United States, also despise the Pakistani government and security forces for co-operating with Washington since the September 11 2001 attacks. The group has carried out numerous attacks on Pakistan's security establishment over the years.
Taliban spokesman Ahsanullah Ahsan said future attacks would also target Pakistan's president, prime minister and army chief, but he said the militants would not assault the country's nuclear installations because "Pakistan is the only Muslim nuclear power state".
"We had announced that we will target Pakistani leaders and Pakistani security forces to punish them for supporting America," he said. "We are carrying out these attacks to prove that we can do what we say."
Government leaders condemned today's bombing.
"Our determination is much higher than before, and we will fight 'til the defeat of these terrorists," said Bashir Bilour, a senior official with the provincial government. He said at least 660lb (300kg) of explosives were used.
Bin Laden was killed on May 2 by a team of US Navy Seals in the army town of Abbottabad, elsewhere in Pakistan's north-west and roughly a mile away from Pakistan's premier military academy.
Since the raid, US-Pakistan relations have sunk to new lows.
Pakistani leaders insist they had no idea the al-Qa'ida leader had been living, apparently for five years, in the large, three-storey house in Abbottabad. And they are furious that the US raided the house without telling them in advance.
Since the bin Laden raid, the Pakistani Taliban has taken responsibility for a twin suicide bombing at a paramilitary police training facility which killed around 90 people and a car bomb that slightly wounded two Americans in north-west Pakistan.
But the siege of the naval base in the southern port city of Karachi was easily one of the most audacious militant assaults in years and further rattled a military establishment already humiliated by the unilateral US raid.
The militants destroyed two US-supplied surveillance aircraft while killing 10 people on the base. Four militants died in the fighting, officials said.
There have been conflicting accounts as to the number of insurgents involved - anywhere from six to 15. Pakistan security agencies are known to sometimes not give full accounts of terrorism incidents and often hold suspects for months without informing the public.
The fact that the attackers managed to infiltrate so deep into the high-security base led to speculation they may have had inside information or assistance.
The military is not immune from the anti-Americanism and Islamism coursing through the country, especially in its lower ranks, and America's raid against bin Laden has exacerbated anger among soldiers.
The naval base stand-off also revived international concerns over whether Pakistan's estimated 100 nuclear weapons were safe from extremists.
During a news conference in Kabul yesterday, Nato Secretary- General Anders Fogh Rasmussen acknowledged the ongoing concerns about the safety of Pakistan's nuclear weapons.
"Based on the information and intelligence we have, I feel confident that Pakistan's nuclear arsenal is safe and well protected," he said. "But of course, it is a matter of concern and we follow the situation closely."