Seven people were killed, including five who were charred to death, and 15 others injured on Wednesday when rival groups of lawyers clashed in Karachi, sparking large-scale violence.
The two groups of lawyers clashed near the office of the Sindh High Court Bar Association, following which groups of armed men exchanged fire at several places in Karachi.
Five persons, including a woman, were burnt alive when a mob torched Tahir Plaza, a building on the busy M A Jinnah Road that has the offices of several lawyers.
Two others were shot dead in separate incidents of firing, police said.
President Pervez Musharraf expressed shock over the violence and directed authorities to take all necessary measures to ensure peace and calm.
He also directed them to bring the "perpetrators and disruptive elements to justice."
Musharraf appealed to the people to cooperate with law enforcement personnel in ensuring peace and tranquillity in the metropolis.
Meanwhile, police said the violence broke out after some lawyers attacked a rally of lawyers belonging to the legal aid committee of the Mutthaida Qaumi Movement, who were holding a protest against the manhandling of former Federal minister Sher Afgan in Lahore on Tuesday night.
Soon the violence spread to other parts of Karachi, including Gurumandir, Malir and New Karachi. Markets and shops across the city were closed and police and paramilitary Pakistan Rangers were deployed to quell the violence.
Gun-wielding men on motorcycles opened fire at several places, creating panic and forcing shop-owners to shut down their establishments.
Miscreants also set ablaze a bank and several buses, trucks and cars in different parts of Karachi.
The office of the Malir Bar Association was gutted and an intense exchange of fire between two groups was witnessed in the area. There were also reports of heavy firing from Shah Faisal Colony, Malir, Burns Road and Jamia Cloth Market.
The violence increased with heavy firing reported from many parts of Karachi.
Police and television reports said that unknown persons had set over 30 vehicles on fire.
Bar association officials said the violence broke out after a group of lawyers disrupted a meeting at the bar office near the city courts.
"We condemn this violence and we are trying our best to keep our workers under control," MQM leader Haider Abbas Rizvi said.
Public transport went off the roads following the violence and people had to face hardship in returning home.
Nabeel Gabol, a Pakistan People's Party parliamentarian from Karachi, said "anti-democratic elements" that were defeated in the recent polls were behind the violence.
Gabol said these elements had been rejected by the majority of the people and the violence was a conspiracy against the PPP.
Prime Minister Yousuf Raza Gillani strongly condemned the violence and appealed to the citizens of Karachi to remain calm and peaceful.
He asked all political forces to maintain peace and harmony in the city in order to support political stability.
Karachi, known for sectarian violence, has been hit by unrest several times in recent months, most recently after assassination of former premier Benazir Bhutto at an election rally in December 2007.