KARACHI, Pakistan - Pakistan on Friday ordered 1,000 extra troops to deploy in Karachi with instructions to shoot-to-kill after up to 70 people were killed in the deadliest six months of political violence since 1995.

Gunfire reverberated in several neighborhoods and thousands of people were stranded, short of food and too frightened to go out after three consecutive nights of violence in what is Pakistan's biggest city and economic hub.

The US ambassador to Pakistan voiced concern about escalating instability in the city, whose Arabian Sea port is used by the United States to ship supplies to the 150,000 foreign troops fighting the Taliban in Afghanistan.

The killings have been blamed on loyalists of former coalition partners the Muttahida Qaumi Movement (MQM) and Awami National Party, which represent different ethnic communities and straddle volatile political fault-lines.

Although the stock market was open, trading was sluggish as most of the city shut down, with shops closed and bus drivers on strike. The dominant local party, MQM, has called for a day of mourning.

"At least 65 people have been killed in the violence since Tuesday. The number of injured is around 100," said Sharjeel Memon, the information minister of the southern province of Sindh.

A security official confirmed the toll.

In the worst incident, gunmen opened fire on two buses, killing 12 people, including a 6-year-old girl overnight, a security official said.

Anwer Kazmi, who works for Pakistan's largest charity, the Edhi Foundation, said it was difficult to deliver food and water because of incessant gunfire.

"Seven of our ambulances have been fired on so far, and one of our volunteers has been shot and injured," he said.

Local residents in troubled neighborhoods spoke of their fear, saying they were running out of supplies and could do little but cower at home.

"The walls of my house are riddled with bullets. Many of our household items have been destroyed. Most of time we duck inside the house to save ourselves from frequent volleys of bullets," said Akber Khan from Orangi neighborhood.

Agence France-Presse

(China Daily 07/09/2011 page8)