There has been a powerful explosion close to the police headquarters in the southern Afghan city of Kandahar, killing at least two people. Officials say a bomb went off in a parking lot for police vehicles. But, they don't know whether the explosives were set off by remote control or by a suicide bomber. Several police vehicles were destroyed and windows in nearby buildings were shattered. Earlier today, a suicide bomber blew off a car near an Army check-point in the north of the country, injuring more than a dozen soldiers and civilians. And yesterday, a roadside bomb in the south of the country killed 15 people.