Afghan Taliban bombers targeting a district centre in southern Afghanistan have killed at least 19 people, including eight election workers, officials said on Sunday.

The attack comes as a new round of talks between the United States and the Taliban to end the 18-year long war in Afghanistan entered a second day in Qatar.

The militants rammed four armoured vehicles packed with explosives into a government compound in Maruf district late Saturday, a police spokesman in southern Kandahar province said.

“Unfortunately 11 policemen were martyred and 27 more injured,” Qasim Afghan told AFP.

Eight election workers who were stationed at the centre to register voters ahead of the presidential polls in September were also killed in the attack, said Zabiullah Sadaat, a spokesman for Afghanistan's Independent Election Commission (IEC).

Afghanistan's twice-delayed presidential election is now slated for September 28.

The Afghan Taliban claimed responsibility for the attack, with a spokesman tweeting that their fighters had captured the district centre, killing 57 security forces.

Afghanistan's interior ministry however rejected the claim, saying in a statement that the militants had been beaten back and 25 insurgents killed.

Afghan President Ashraf Ghani condemned the “barbaric and unforgivable” attacks, which are the latest in a relentless wave of assaults by the Taliban, who now hold sway over about half of the country and regularly target government forces.

The insurgents killed at least 25 members of a pro-government militia in an attack in northern Baghlan province on Saturday.

The violence comes amid stepped-up efforts by the United States to find a negotiated end to America's longest war, with Washington and the Taliban opening a fresh round of negotiations in Doha on Saturday.