KANDAHAR, Afghanistan, June 5 (Xinhua) -- One police officer has been killed and two others wounded following a heavy explosion in Afghanistan's southern Kandahar province, provincial governor spokesman said Tuesday.

The blast happened late Monday night at Police District 12 of provincial capital Kandahar city, resulting in the casualties, spokesman Daud Ahmadi told Xinhua.

One police vehicle was also damaged in the blast.

No armed group has so far claimed responsibility for the attack.

Security situation has been improving in Kandahar, the former stronghold of Taliban, over the past months, as security forces have conducted search and cordon operations across the province. But militants attack government interests in the province from time to time.