Terrified residents took shelter Saturday as gunfire and other violence swept through the southern port city of Karachi.
Police and witnesses say the fighting began Saturday morning.
Thousands of pro-government activists roamed the city streets as opposition groups attempted to gather to support the country's suspended chief justice, Iftakhar Mohammed Chaudhry.
Pakistani television showed people marching through Karachi streets carrying handguns, assault rifles and flags of a pro-government party. Scores of vehicles were set on fire.
Talat Hussain is the news director for Pakistan's Aaj Television network. Speaking by phone from Karachi he says pro-government gunmen attacked the network's offices after it showed live footage of the violence outside.
"This is like a battlefield. There is no law enforcement in sight and bullets are flying all around."
Officials say more than 15-thousand police and para-military forces were deployed throughout the city.
The former chief justice spent most of the day stranded inside Karachi's main airport and was ultimately forced to cancel plans to address his supporters.
Pakistan President Pervez Musharraf addressed his own political rally in Islamabad Saturday night, several hours after the situation in Karachi appeared to be improving.
He says he will not impose any emergency restrictions on the country. He says there is no need to take such extreme measures and the country's democracy will continue its course.
He said national elections will be held later this year.
Pakistan Musharraf suspended Chaudhry on March 9 over unspecified allegations that he abused his authority.
The move sparked protests around the country and remains one of greatest political crises President Musharraf has faced since he seized power in a 1999 military coup.
His critics say Mr. Musharraf only removed the judge to gain control over the country's judiciary ahead of those planned national elections.
He is expected to seek another five-year presidential term while also remaining the country's military chief, a move his critics say is unconstitutional and subject to challenge in the country's high court.
Opposition parties are demanding the judge either be reinstated or that Mr. Musharraf resign from office.
Neither side has made any move toward compromise and the political standoff shows no signs of lessening.