Streets are dark because snipers have shot out most of the lights. Inside homes, people cringe with each burst of gunfire.

This is Liaqatabad, a poor neighborhood in central Karachi caught in a relentless war between rival factions of a refugee group. It is a place where young gunmen on roof-tops shoot at police, residents and rivals alike, a battle zone so dangerous even the police are afraid to enter."It is now impossible to live here anymore," said Mohammed Far-eed, a resident and shop owner. "But there is no one who wants to buy my house."

The combatants are members of the Mohajir Qami Movement, which represents Muslims who moved to Pakistan from predominantly Hindu India after the British colonialists pulled out in 1947.

Millions of the immigrants - known as Mohajirs, or refugees - settled in Sindh Province, whose capital is Karachi, Pakistan's biggest city. They long have claimed the national government ignores their needs and discriminates against them in favor of indigenous ethnic groups.

Frustrated by a lack of progress, militant Mohajirs turned to violence to press demands for equal access to government jobs and places at universities and other state schools. They soon built up an arsenal of heavy weapons that often are better than those of Karachi's police force.

Several years ago the militants split over power and political goals. Rivals began to openly clash, taking over entire neighborhoods of Karachi, a sweltering city of 14 million people. Gunmen roaming eastern neighborhoods killed three people Saturday, set vehicles on fire and shut down shops, according to witnesses and police.

Fighting among the Mohajirs ebbs and surges depending on the sporadic efforts of the national government to crack down. A heavy-handed campaign in 1995, during which human rights groups accused police of murdering captured militants, brought a two-year lull for Karachi.

But bloodshed erupted again June 1. Since then, more than 200 people have been killed, many of them civilians caught in the crossfire. A young girl was shot while running to the market. A small boy returning home from school was slain.