Updated

A suicide bomber killed 12 policemen in the southern Afghan province of Uruzgan on Friday when he blew himself up inside a police station as officers ate lunch in a dining hall, officials said.

The bomber targeted a base used to patrol the main road from Uruzgan to neighbouring Kandahar province, through one of Afghanistan's most volatile regions where Taliban militants have a strong presence.

"A suicide bomber detonated his explosives in a battalion station in Tirin Kot, the provincial capital," Abdullah Hemat, the Uruzgan governor's spokesman, told AFP.

"The bomber, who was on foot and wearing a suicide vest, blew himself up while the policemen were having lunch. As a result, 12 policemen were killed and five others wounded," he said.

The attack was the second suicide strike in Afghanistan on Friday after another bomber detonated himself at a border crossing with Pakistan, killing two people including a senior Afghan police commander.

The attacker had crossed from Pakistan to Spin Boldak on the Afghan side, Afghan officials said.