A roadside bomb ripped through a police vehicle in southernAfghanistan, killing a district police chief and two of his bodyguards, authorities said on Monday.

The blast happened late Sunday as the group drove from Lashkar Gah, the capital of troubled Helmand province, to Garmser district.

"Mohammad Saifullah, the police chief of Garmser district in Helmand province, was killed along with two bodyguards when a roadside bomb hit their vehicle last night," said Helmand police chief Mohammad Hakim Angar.

Helmand has been one of the bloodiest battlefields of the Afghan war, although foreign forces say they have rooted out some key insurgent strongholds in recent months following a troop surge.

Lashkar Gah was one of seven areas handed over to Afghan government control by NATO-led forces in July in a first wave of transition which will see all foreign combat troops leave by the end of 2014.

Sunday's attack happened on the same day seven people were killed by a suicide bomber as they returned from prayers at the start of the Muslim holiday Eid al-Adha in Baghlan city, northern Afghanistan.

Elsewhere in Baghlan province Monday, six police officers were wounded when a suicide car bomber blew himself up when targeting the house of a local elder involved in efforts to make peace with the Taliban in the area.

The attack in Puli Khumri also involved a second raider who exchanged fire with police after the blast but later escaped, Baghlan police chief Asadullah Shirzad said.

He added that the injuries to police were not life-threatening and a hunt for the escaped attacker had been launched.