A suicide bomber riding a motorcycle has attacked a police checkpoint in north-western Pakistan, killing 13 people, police said.
The blast in Swabi town, 44 miles from the capital Islamabad, struck a crowd gathered along the road to greet a prominent hardline Islamist politician.
It is unclear if the bomber specifically targeted the supporters of politician Maulana Fazlur Rehman or if they just happened to be there when he hit the checkpoint.
Mr Rehman has been an outspoken supporter of the Afghan Taliban, but some militants in Pakistan have shown a willingness to attack anyone connected to the government.
The bomber detonated his explosives just outside the checkpoint when a policeman told him to halt, said Saeed Khan, a police official at the main communications centre in Peshawar city.
The blast killed the policeman and 12 civilians, said Mr Khan. Another 12 people were wounded.
Mr Rehman, the leader of the Jamiat Ulema Islam party, passed through the checkpoint minutes before the bomber struck and was unharmed, said Mr Khan.
The politician was travelling to Charsadda town to address a public gathering.