A new wave of vilence that erupted over the weekend brought up the number of casualties to 44 whereas casualties were reported in the city's eastern Malir, Landhi and adjoining areas -- a multi-ethnic, lower middle class neighborhood.
"We have identified the people and at least 200 police commandos will be dispatched to search and arrest these people," said Naeem Boroka, a senior police official in Karachi's eastern area.
Police said there was no clear reason for the latest bout of fighting. The city, home to more than 18 million people, has a long history of ethnic, religious and sectarian violence and local quarrels and political disputes can often explode into battles engulfing entire districts.
The areas affected are home to both Pashtuns and Muhajirs, the descendents of Urdu-speaking refugees who fled India to settle in Karachi in 1947 following the sub-continent's partition. The two political parties representing the two ethnic groups have a history of enmity and violence between them.
But the recent fighting also included Sunni-Shi'ite violence, with personal feuds played out in an environment that has seen a breakdown in law and order, said Sindh Information Minister, Sharjeel Memon.
The Muhajir-backed Muttahida Qaumi Movement, the Pashtun-backed Awami National Party and the Pakistan People's Party have often used street thugs and ethnic gangs over the years as footsoldiers in a city-wide turf war over political power in Karachi, which contributes 68 percent of Pakistan's tax revenues and hosts the country's largest ports.
Karachi was a main target of al Qaeda-linked militants after the September 11, 2001 attacks on the United States, when Pakistan joined the U.S.-led campaign against militancy, and foreigners were attacked in the city several times.
A recent report from the Human Rights Commission of Pakistan said 1,138 people were killed in Karachi in the first six months of 2011, of whom 490 were victims of political, ethnic and sectarian violence.