At least 12 people were killed and scores others wounded on Thursday when the Taliban attacked a police headquarters in the southern city of Kandahar, officials and the militants said.

The assault comes amid a series of peace talks between Washington and the Taliban that both sides say are making progress, but which so far have yielded no reduction in violence in the gruelling Afghan conflict.

Taliban spokesman Qari Yousuf Ahmadi said the afternoon attack in Afghanistan's second-largest city started with a car bomb, then saw gunmen storm the police compound.

“A number of mujahideen equipped with heavy and small arms breached the headquarters and launched their operations inside,” he said.

Baheer Ahmadi, the Kandahar governor's spokesman, told AFP that 12 people had been killed, including nine civilians and three police officers. Another 89 were wounded, he added.

Take a look: Kandahar governor, police and intelligence chiefs killed in insider attack

Police chief Tadin Khan said the car bomb was followed by two other explosions. “The fighting is over now. Some vehicles were burnt. Now the Afghan army and US helicopters are hovering in the area,” he told AFP.

Hayatullah Hayat, the provincial governor for Kandahar, said Afghan security forces had launched a “clean-up operation” to see if any attackers were remaining.

Pictures on social media showed a huge plume of smoke rising over Kandahar, and Hayat said about six trucks carrying commercial goods had burnt.

The assault comes just one day after two Afghan soldiers — who were really Taliban operatives — fatally shot an Afghan colonel in Ghazni province.