Other 19 people were wounded in the blast in a car park outside the police building, the local government said.
The blast – thought to have been caused by explosives hidden inside a parked car and detonated remotely – was strong enough to shatter nearby windows.
No-one has yet claimed responsibility for the attack.
Kandahar is the largest city in southern Afghanistan and the province is considered to be the spiritual homeland of the Taliban.
Militants frequently launch attacks against government and military targets in the province, despite intensive efforts by NATO-led forces in recent years to improve security there.
The United Nations said on Saturday that civilian deaths in Afghanistan had risen for the fifth year in a row – with 3,021 deaths in 2011 compared with 2,790 in 2010 and 2,412 in 2009.
The US House Ethics Committee has voted to release its report on former Republican Representative…
ABC News has agreed to pay $15 million to President-elect Donald Trump to settle a…
South Korea’s parliament has voted to impeach President Yoon Suk Yeol over his failed attempt…
Israeli war planes have carried out more than 100 air strikes in Syria on December…
President-elect Donald Trump has threatened to impose 100% tariffs on the BRICS countries if they…
Syrian troops have withdrawn from the city of Aleppo following an offensive by rebels opposed…