Decision to impose the partial curfew was made by Interior Minister Rehman Malik and Chief Minister Sayed Qaim Ali Shah after rejecting proposal from one of the coalition partners in Sindh government, the Awami National Party, which demanded that the riot-torn city should be hand over to army.

Tensions are high between the Muttahida Qaumi Movement (MQM) and the Awami National Party (ANP), which each represents rival communities in Karachi, a city straddling political fault lines.

“A semi-curfew will be imposed in some areas of Karachi,” Interior Minister Rehman Malik said in a brief televised interview with reporters, after meeting top officials in Karachi.

Malik did not explain what he meant by “semi-curfew,” but Sindh Home Ministry spokesman Sharfuddin Memon said, “It is for the authorities to decide for how long they would like a troubled area to remain under curfew.”

Malik also called the MQM chief Altaf Hussain in London to assure him that those involved in the killing of his party activists will be arrested soon.

Dozens of suspects linked to the killings have been rounded up, with extra police and paramilitary rangers deployed in Karachi’s trouble-prone western neighborhoods.

“It is responsibility of the federal and provincial governments to protect the people,” Malik said, justifying the decision to impose the partial curfew, without disclosing which areas would be affected.

Malik also said, without elaborating, that there was “a third element trying to deteriorate the situation in Karachi.”

— With input from agencies