Suicide bombers attacked a police training center on Monday in southern Afghanistan's largest city, officials said.
A midday blast that struck the compound could be heard throughout a number of Kandahar city neighborhoods. Southern region Police Chief Gen. Shafiq Fazli confirmed that the blast hit the training center but did not give further details. There were no immediate reports of casualties.
Gunfire could be heard coming from inside the training center, which swarmed with Afghan and NATO troops.
A police officer inside the compound told The Associated Press that four assailants attacked the center, two of whom detonated their explosives immediately. The remaining attackers appeared to be fighting with NATO and Afghan forces. The officer spoke on condition of anonymity because he was not authorized to speak to journalists.
Kandahar city has been struck by a series of militant attacks in recent weeks and months - most claimed by the Taliban as part of their counteroffensive to a NATO push into their southern strongholds.
NATO has pledged to make the coming offensive a combination of military strikes and government-boosting programs it hopes will win over the population.
No one immediately claimed responsibility for Monday's attack, but Taliban militants were the most likely perpetrators. They have struck the city with a slew of bombings and assassinations of people seen as government allies.