Four men strapped with explosives have stormed a provincial governor's compound in western Afghanistan, officials say.

Six police and one civilian were killed in Thursday's attack in addition to the fighters.

The attack targeted the offices of Mohammad Akram Khpalwak, current governor of southwestern Farah province.

The assault began at 10:30am local time (04:30 GMT), when a suicide bomber detonated his explosives, killing himself at the entrance to the compound, Shamsul Rahman Zahid, the provincial police chief, told local media.

A group of armed suicide bombers dressed in Afghan National Police uniforms then stormed the compound.

"Four suicide attackers who stormed the governor's compound exchanged gunfire with the police," the governor's spokesman Naqeebullah Farahi, told the AFP news agency.

Attackers killed

Al Jazeera's Bernard Smith, reporting from Kabul, said the AK-47 wielding attackers either detonated their explosives or had been shot dead in a firefight with police.

He said the attack falls in line with recent Taliban strategies of "targeting high profile locations ... [and] high profile individuals", with a tendency to employ multiple suicide bombers in the attacks.

In mid-April, dozens of people were killed and injured when Taliban suicide attackers occupied construction sites in Kabul, including one at the heart of the diplomatic enclave, unleashing a battle with security forces that lasted
about 19 hours.

No group has so far taken responsibility for the attack.

The interior ministry blamed it on "terrorists", a phrase Afghan officials often use to refer to the Taliban.

The incident in the relatively peaceful province comes days before this weekend's NATO summit in Chicago, where the security situation in Afghanistan beyond a 2014 international troop withdrawal will be discussed.