A suicide bomber killed two pakistani policemen and wounded five others as security forces tried to stop him from walking into their local headquarters on Monday, police said.
The bomber blew himself up outside the Shah Mansoor compound of police offices and residences in Swabi, 100 kilometres (60 miles) northwest of Pakistan's capital Islamabad.
"Two policemen were martyred and five others were injured when a suicide bomber exploded himself after being stopped at the main gate," senior police official Abdullah Khan told AFP.
"Three men came in a car. One of them (the bomber) got out of the car and moved towards the main gate. When policemen stopped him, he blew himself up."
Police open fired at the bomber's accomplices but they fled, Khan said. More than 3,740 people have been killed in suicide attacks and bombings, blamed on homegrown Taliban and other Islamist extremist networks, since government troops stormed a radical mosque in Islamabad three years ago.
According to the Pakistani military, 2,421 army and paramilitary soldiers were killed and 7,195 wounded in fighting with Islamist militants from 2002 until april this year.