At least seven people have died in a suspected bomb blast near a police post in the Pakistani city of Lahore.
At least nine people were hurt in the explosion. It is unclear if the blast was caused by a suicide bomber.
The attack comes as Pakistan prepares to celebrate the 61st anniversary of its independence on Thursday.
Pakistani security forces are often attacked by Islamist militants allied to the Taleban militia based in the rugged north-west of the country.
Twelve militants were killed in a missile strike in north-western Pakistan on Tuesday.
Thirteen people also died in the north-western city of Peshawar in a bomb attack on an air force bus on Tuesday.
Thursday's attack in Lahore appears to have targeted policemen on guard duty for the Independence Day celebrations.
According to AFP news agency, a policeman interviewed by the private Express TV station said he had seen the burning body of motorcyclist, whom he believed to be a suicide bomber, lying next to bloodied policemen.
"It appears the motorcycle rider blasted them. His body was making burning noises," the policeman was quoted as saying.