The aftermath of the suspected bomb blast in Peshawar
At least 49 people have been killed in a bombing in a crowded area of the north-western Pakistani city of Peshawar, officials say.
More than 100 people have also been injured in the suspected suicide bombing, a regional minister said.
Officials said a vehicle laden with explosives had been detonated near the city's Khyber Bazaar.
Friday's explosion was the latest in a series of recent bombings across north-western Pakistan.
M Ilyas Khan, BBC News, Islamabad
The renewed Taliban campaign coincides with increased speculation about the start of a major ground offensive in South Waziristan - the epicentre of militancy in Pakistan.
This shows a change of tactics. Instead of spectacular attacks against military, police, sectarian or Western targets, militants are focusing on low-intensity bombings to cause general terror.
The bomber used less than 50kg of explosives, laced with bearings and shells to cause maximum damage in a crowded civilian location.
It could also indicate a decline in the ability of the militants to penetrate high-value targets with large bombs.
It comes as the Pakistani army prepares an operation against the Taliban in the tribal region of South Waziristan.
TV footage showed what appeared to be the charred frame of a bus destroyed by the explosion. Many of the victims of the blast were thought to be passengers and police said this included a number of children.
The remains of other vehicles were strewn in the road.
Officials said they thought a suicide bomber travelling in a car had carried out the attack.
"He blew himself up as the car was next to a passenger bus passing through the market," senior police officer, Shafqat Malik, told the BBC.
It is the deadliest attack in Pakistan since March when a suicide bomber destroyed a crowded mosque in Jamrud, killing at least 50 people.
But doctors at the Lady Reading hospital, close to the blast site, warned that the toll could rise as many of the injured were in a critical condition.
Pakistani officials emphasised the government's resolve to tackle militancy on a wider scale.
"One thing is clear, these hired assassins called Taliban are to be dealt with more severely," Interior Minister Rehman Malik told reporters.
"I think the incident of today has accelerated this," he added. "We think we have no other option except to carry out an operation in South Waziristan because every matter, every incident, whatever is happening, all roads are leading to South Waziristan so I think we'll have to proceed."
A witness at a local hospital told the Associated Press news agency that he had seen the vehicle explode.
"I saw a blood-soaked leg landing close to me," he said. "I understood for the first time in my life what a doomsday would look like."
Witnesses also described how bystanders desperately tried to free survivors trapped in vehicles overturned by the force of the explosion.
Hours earlier, police said gunmen in Peshawar had attacked vehicles being used to take supplies to Nato forces in Afghanistan, setting them on fire and destroying them.
NORTH-WEST PAKISTAN BLASTS
5 October: Five killed in suicide blast in UN's Islamabad office
26 September: 16 killed in two car bombs in Peshawar and Bannu
18 September: 33 killed in market blast near Kohat
30 August: Suicide bomber kills 14 police recruits in Swat valley
27 August: 22 police guards killed at checkpoint on Afghan border
14 August: Seven killed in market blast in Dera Ismail Khan
5 June: Mosque blast kills at least 38 in Upper Dir district
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