|Political activists march for an end to the violence that has engulfed Karachi this year [AFP]
Deadly street fighting has spilled over from the weekend in Karachi despite efforts by officials to stop violence in the city that is home to the country's main port, stock exchange and central bank.
Police said on Monday 17 people were killed in the city since early Sunday in fighting linked to ethnic and religious tension, adding that about 200 people were killed in the city in July alone - one of the deadliest months in Karachi in about two decades.
Most of the areas affected in the latest violence are home to ethnic Pashtuns as well as Mohajirs, the descendants of Urdu-speaking refugees who fled India to settle in Karachi in 1947 after the subcontinent's partition.
Street thugs and ethnic gangs have been used by political parties over the years as foot soldiers in a city-wide turf war in Karachi, which contributes 68 per cent of Pakistan's tax revenues.
"There is no question about the fact that the violence is politically and ethnically motivated, so the solution has to be political too," a senior police official, requesting not to be named, said.
"We have seen a peace initiative from the government as well as the political parties. But I think the stakeholders need to be more sincere in their efforts to restore peace."
Other officials said there was no clear reason for the latest bout of fighting, which erupted from the western Orangi town neighbourhood early in July, when about 100 people were killed in only three days. Violence also flared last week.
Paramilitary Rangers took control of the Orangi area, but violence has since spread to other parts of the city, home to more than 18 million people.
A recent report from the Human Rights Commission of Pakistan (HRCP) 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.
In another statement issued on Monday, the HRCP called for a political solution to the violence in Karachi.
"Karachi is in the grip of a multisided wave of insecurity-driven political, ethnic and sectarian polarisation
that has greatly undermined its tradition of tolerance and good-neighbourliness," it said.
"While gangs of land-grabbers and mafias have tried to exploit the breakdown of law and order, they do not appear to be the main directors of the horrible game of death and destruction; that distinction belongs to more powerful political groups and it is they who hold the key to peace."
Sharjeel Memon, the information minister of Sindh province, of which Karachi is the capital, said "peace efforts" were continuing.
"The peace initiative is still continuing and all the stakeholders are on board for this," Memon told the Reuters news agency.
"There are elements which do not want peace in Karachi, but we are hoping that peace would be restored in the city soon."