Suicide attack on Kabul voter registration centre kills four

A suicide bomber blew himself up in a crowd outside a voter registration centre in the Afghan capital Kabul on Sunday, killing four people and wounding 15.

"It happened at the entrance gate of the centre. It was a suicide attack. There are casualties," Dawood Amin, city police chief, told AFP.

Health ministry spokesman Waheed Majroh said at least four people had been killed and 15 wounded.

The attack -- the latest assault targeting a voter registration centre -- happened in a heavily Shiite-populated neighbourhood in the west of the city. Afghanistan on April 14 began registering voters for long-delayed legislative elections scheduled for October.

Election officials have acknowledged that security is a major concern as the Taliban and other militant groups control or contest large swathes of the country.

Afghan police and troops forces have been tasked with protecting polling centres, even as they struggle to get the upper hand against militants on the battlefield.