Pakistan's biggest city Karachi shut down today after a senior politician belonging to the city's dominant Muttahida Qaumi Movement (MQM) was stabbed to death in London.
Imran Farooq, a founding member of the MQM party, the most influential in Pakistan's commercial capital Karachi, was killed last night but it was not clear if it was politically motivated.
Dr Farooq, inactive in politics for about two years, claimed asylum in Britain 11 years ago after more than seven years on the run from Pakistani police who accused him of involvement in murder and other serious crimes. He denied the charges.
Even though he is not an influential MQM figure, the killing could trigger more ethnic and political violence in Karachi.
Most shops and schools were closed and no public transport was available after the MQM announced 10 days of mourning.
A few vehicles were torched, police said.
"We are confident that the culprit will be arrested and will be given exemplary punishment," Farooq Sattar, a senior member of the MQM and a minister in the government of president Asif Ali Zardari, told reporters in Karachi.
Sattar refused to speculate on the motives behind the killing, saying they were awaiting results of British investigations.
London police said Dr Farooq had been found with stab wounds and head injuries outside his home in Edgware, north London. He was treated by paramedics but pronounced dead at the scene.
They said Dr Farooq, 50, had been on his way home from work when he was attacked. They appealed for witnesses and said there had been no arrests so far. Counter-terrorism officers are leading the investigation, they said.
"The murder of Dr Farooq is shocking for the Edgware, Pakistani and Muslim communities. I would like to reassure these communities that specialist detectives ... are working around the clock to catch those responsible," a local police commander, Chief Superintendent Neil Basu, said in a statement.
Up to 100 people were killed and hundreds wounded in several days of clashes in Karachi last month after MQM member Raza Haider, who was a Shia Muslim, was gunned down along with his bodyguard while attending a funeral.
The government blamed the Taliban and the banned Sunni Muslim militant group Sipah-e-Sahaba Pakistan (SSP) for the killing of the parliamentarian.
Dr Farooq was one of several senior members of the MQM who have taken refuge in London. The party's top leader, Altaf Hussain, has lived in self-exile in the British capital since 1992.
Reuters