A suicide bomber drove a vehicle packed with explosives on to a field during a volleyball tournament in northwest Pakistan today, killing at least 70 people.
Police said that at least 65 people were wounded and some 20 houses destroyed in the attack.
The blast occurred near Pakistan's tribal belt, and was the latest in a series of attacks in the country since the Army launched a military offensive against Taleban fighters in the South Waziristan tribal region. More than 500 people have died in reprisal attacks.
Police said that today's bombing in Lakki Marwat city, not far from South Waziristan, was possibly in retaliation for local residents' efforts to keep militants out of the area.
"The locality has been a hub of militants. Locals set up a militia and expelled the militants from this area. This attack seems to be a reaction to their expulsion," Ayub Khan, the local police chief, told reporters.
He said that the bomber drove on to the field, which lies in a congested neighborhood, during the volleyball contest. Some nearby houses collapsed, and Mr Khan said that police feared that ten or more people may be trapped in rubble.
In North Waziristan a suspected US missile struck a car carrying alleged militants, killing three men, intelligence officials said. It was the second such strike in less than a day.
The strikes are part of an American campaign to eliminate "high-value" militants who use Pakistan as a safe haven to plan attacks in neighbouring Afghanistan and on the West.