Four gunmen attacked a minibus carrying Shiite Muslims in southwestern Pakistan on Thursday, killing eight of them, police said.

The Shiites from the minority Hazara community were targeted outside the vegetable market on the outskirts of Quetta city, operations police chief Aitzaz Goraya said.

The four gunmen riding two motorcycles killed six men in the minibus and chased another two down before shooting them dead, he said. Another two people were wounded.

No one has claimed responsibility, and the officer said it was not clear who carried out the attack.

Suspicion likely is to fall on Sunni extremists, who have often targeted Shiites in the past. Previous attacks have been claimed by the Sunni militant groups Lashkar-e-Jhangvi and the Pakistani Taliban.

The Pakistani Taliban have been on the run since the launch of a Pakistani military offensive in their last remaining safe havens in North Waziristan, a tribal region near Afghan border.

The local Taliban have been waging a war against the state in a bid to topple the government and impose their harsh brand of Islamic law, and have killed thousands of Pakistanis over the last decade.

Quetta city is the capital of Baluchistan province, which is also home to Baluchi separatist and nationalist groups. The nationalists have been fighting for autonomy and a greater share of revenues from the region's natural resources.

A suicide bombing on Oct, 4 killed five people of the Hazara Shiite community in the city. Members of the minority community based in the southwest stand out because of their facial features.

Goraya and another official, Shahzada Farhat, said the Hazara had been given police escorts for security but that those who were targeted were unaccompanied because they had not informed police in advance of their movements.

Pakistani television ran live footage of the scene showing police removing bodies and helping wounded people as family members of the deceased cried and wailed.

Hundreds of Hazara later blocked a main road in the city to protest the killings.