Attacks in Pakistan's troubled south-western province of Baluchistan, including an assault on the country's beleaguered minority Shiites Muslims and a suicide bombing targeting a pro-Taliban cleric, have killed 12 people on Thursday.

All the attacks took place in the provincial capital of Quetta.

In one attack, near a vegetable market on the city's outskirts, four gunmen on motorcycles sprayed a minivan carrying Hazara Shiites with gunfire, said police.

Six men died on board the bus while the gunmen chased down another two as they tried to flee and shot them dead. Two other people on the bus were wounded.

Pakistani television broadcast footage from the scene, showing police removing bodies of the dead and helping the wounded as family members of the deceased cried and wailed.

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

No-one immediately claimed responsibility for the attack, and police said it was not clear who was behind it.

But suspicion is likely to fall on Sunni extremists, who have often targeted Shiites in the past.

In the past, attacks on Shiites were often claimed by the Sunni militant groups Lashkar-e-Jhangvi and the Pakistani Taliban.

In June, the Pakistani military launched an offensive in the country's main Taliban stronghold in North Waziristan, a tribal region near Afghan border.

The Taliban have been waging a war against the state there 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.

Baluchistan is home to Baluch separatist and nationalist groups that have been fighting for autonomy and a greater share of revenues from the region's natural resources. A suicide bombing earlier in October in Quetta killed five Hazara.

Officers said the Hazara are often given police escorts for security but that those targeted today were unaccompanied because they had not informed the police in advance of their trip.

Later, a bomb rigged to a motorcycle exploded near an army patrol in Quetta, killing two civilians and wounding 10 people, including two paramilitary soldiers. The bombing happened about 1.4 miles (2km) away from the site of the attack on the Hazara.

By dusk, a suicide bomber detonated his explosives-laden vest next to a bullet proof car carrying Maulana Fazlur Rehman, the chief of the Taliban-linked Jamiat Ulema-e-Islam religious party.

Mr Rehman, who had just finished addressing a rally of thousands of supporters in Quetta, survived the attack, which killed two people and wounded several others.

The religious party is based in Pakistan but has links with the Taliban in neighbouring Afghanistan. Mr Rehman's religious schools had been one of the main breeding grounds for the Afghan Taliban.

He has previously survived at least two attempts on his life.

"I never know who wants to kill me," he told Pakistani Geo News TV. "Maybe because I talk against America, or because I work for the enforcement of the Islamic system."