Security services rushed to the court building in Peshawar
A bomb attack outside a court in the north-western Pakistani city of Peshawar has killed at least 19 people and injured many others, medics say.
The blast on the busy Khyber Road came during rush hour and is the latest in a series in the city in recent weeks.
Previous blasts have been blamed on Taliban militants.
Attacks across Pakistan have increased dramatically as the army continues its offensive against the Taliban in South Waziristan near the Afghan border.
The head of the Peshawar city administration, Sahibzada Anees, told reporters that a suicide bomber had carried out the latest attack.
"The bomber blew himself up when he was being body searched by a police guard at the gate of the court complex," he said.
Dr Sahib Gul, head of Lady Reading Hospital, told reporters that 19 people were killed in the attack and 51 wounded. Three of the dead are policemen.
A bomb disposal squad official said the bomber used about 10kg of explosives. Several vehicles were destroyed in the blast.
Security officials have cordoned off the area and Khyber Road has been closed for traffic.
Peshawar, near the Afghan border, has been targeted repeatedly in recent months.
Last Friday, a suicide car bomb attack on the office of Pakistan's main intelligence agency ISI on the same road killed at least 12 people and injured 40 others.
And on 28 October, at least 100 people were killed after a huge car bomb ripped through Peshawar's busy Peepal Mandi market.
The court building most recently attacked is also close to the Pearl Continental Hotel, which was targeted by a truck bomb earlier this year.
The attacks come as Pakistan is carrying out an offensive in South Waziristan, which is considered to be one of the main sanctuaries for Islamic militants outside Afghanistan.
Security has been stepped up across Pakistan, but correspondents say the government still appears to be unable to stop the attacks.