The death toll in rioting in Karachi on Thursday rose to 12 as the provincial government ordered a probe into the violence that erupted following clashes between lawyers supporting President Pervez Musharraf [Images] and their rivals.

Six persons, including a woman, were burnt alive after a mob on Wednesday torched a building near the city courts that has the offices of several lawyers. Two other persons were shot dead in incidents of firing while four more succumbed to their injuries in hospital.

The trouble started shortly after a group of lawyers affiliated to the Muttahida Qaumi Movement organised a demonstration to protest the manhandling of Pakistan Muslim League-Q leader and former federal minister Shar Afghan Niazi by a mob of lawyers in Lahore [Images] on Tuesday.

The MQM alleged its lawyers were attacked by a rival group from the Karachi Bar Association. The association refuted the claim and said its rivals had attacked its office and members.

Sindh Chief Minister Qaim Ali Shah said two persons had been arrested in connection with the riots and arms recovered from them. He ordered a probe into the violence and said the report of its findings will be made public within three days.

Shah also directed law enforcement agencies to restore normalcy in Karachi and ordered the paramilitary Pakistan Rangers to increase patrolling.

Following the clashes between lawyers, violence spread to many parts of Karachi, including Gurumandir, Malir, Korangi, Landi and New Karachi.

Markets and shops across the city were closed as gun-wielding men on motorcycles opened fire at several places.

Miscreantsset ablaze a bank and over three dozen buses, trucks and cars in different parts of Karachi.

The office of the Malir Bar Association was torched and an intense exchange of fire between two groups was witnessed in the area.

There was also heavy firing in Shah Faisal Colony, Malir, Burns Road and Jamia Cloth Market.