Kandahar: Twelve policemen and a child were killed on Sunday when a suicide car bomber struck outside police headquarters in the southern Afghan city of Lashkar Gah, officials said.

The attack came days after control of security in the city, the capital of Helmand province, passed from British to Afghan forces as part of a process that will see all foreign combat troops leave Afghanistan by the end of 2014.

Some experts question the ability of Afghan soldiers and police to protect their country against attacks from the Taliban, who claimed responsibility for the latest blast, and other insurgents.

The interior ministry confirmed the death toll and vowed the attack would not prevent the police from battling the Taliban, leaders of a 10-year insurgency raging across the country.

"Twelve Afghan National Police members and a child were martyred and 12 other Afghan National Police members were wounded (along with) two civilians," it said in a statement.

"The Ministry of Interior strongly condemns the insurgents (behind) this un-Islamic and inhumane action and such attacks will never weaken the determination of Afghan National Police."

The blast happened at around 0830 IST (0400 GMT) in front of the heavily-secured police headquarters as Afghan police left to go on a patrol, a statement from the governor's office added.