A bomb rigged to a bicycle has hit a Pakistani police patrol on its way to guard a polio vaccination team, killing six policemen and a boy.
A Pakistani police officer, Shafiullah Khan, says the bombing took place this morning in the Charsadda district in the country's north-west.
He says the bomb, which was set off by remote control, struck close to a busy town market. The blast also wounded 11 people.
The killed boy was just a bystander.
The bombing came just hours after a car bomb hit a bus carrying Shiite pilgrims in a troubled region of south-west Pakistan, killing 20.
And yesterday, three health workers were killed in an attack on a polio vaccination team in southern city of Karachi.