ISLAMABAD, Pakistan -- Men armed with assault rifles battled for hours yesterday in a confrontation between pro- and anti-government forces that raged through residential neighborhoods in Karachi, the country's largest city, killing at least 28 people and injuring more than 100 others.
The strife in the volatile port city of 15 million people, which has a long history of political violence, was the worst yet during a crisis that erupted two months ago when President Pervez Musharraf suspended the country's top judge.
Backers of Musharraf appeared to be the driving force behind the violence in Karachi.
Pakistan is an important American ally in the fight against al-Qaida and the Taliban, both of which have been using the wild border between Afghanistan and Pakistan as a base for planning attacks against Western targets, including the NATO-led force in Afghanistan.
In a Karachi neighborhood close to the international airport, smoke billowed from burning barricades, panicky motorists abandoned their vehicles and residents of high-rise apartment buildings rushed for cover in inner rooms as the chaotic fighting continued through much of the day.
Musharraf, speaking at a rally in the capital, Islamabad, appealed for calm but stopped short of declaring martial law in Karachi.
"If you are unhappy about what has happened ... halt these protests," the president, who took power in a bloodless coup in 1999, told nearly 50,000 supporters in the capital. "There is no need for an emergency - the people are with me."
The political confrontation began March 9, when Musharraf suspended the country's most senior justice, Iftikhar Chaudhry, accusing him of misconduct. But many people believed that the president was seeking to push aside the Supreme Court chief justice to preclude a challenge to the validity of elections to be held this year.
A judicial panel is examining Chaudhry's suspension, but it could take months to reach a conclusion.
The fighting between pro- and anti-government forces broke out just before Chaudhry was to address a large gathering of lawyers, who have rallied to his cause in nationwide gatherings. He was expected to call for his reinstatement, and to urge Musharraf to either step down or give up his military role - a stance that his backers believe was the reason he was suspended from his post.
Opposition parties said the violence was orchestrated by the pro-government Mutahida Qami Movement, or MQM, which controls the municipality. Leaders of the opposition, who had planned to greet Chaudhry at the airport, said police stood idly by as they were beaten and intimidated at the airport, and during violence that subsequently spilled over into large areas of the sprawling city.
Mubashir Zaidi and Laura King write for the Los Angeles Times.