By Syed Raza Hussan
ISLAMABAD (Reuters) - Supporters of an influential Pakistani political party took to the streets of Karachi on Monday to protest against cricket-hero-turned-politician Imran Khan, who has accused it of killing one of his senior staff a week after a general election.
Furious members of the Muttahida Quami Movement (MQM) have denied responsibility for the killing of Zara Shahid Hussain on Saturday outside her home in the upscale Defence area of Karachi, capping a bloody election in which about 150 people were killed nationwide.
MQM leaders condemned the killing by unidentified gunman and demanded a retraction from Khan.
The May 11 elections gave the MQM 18 of 19 national assembly seats in Karachi, which has long been the party's power base. Khan's party won a re-vote in part of one constituency of Karachi on Sunday, giving it one seat and also angering the MQM.
About 3,000 MQM joined the protest to denounce Khan, whose Pakistan Tehrik-i-Insaf (PTI) party was to hold a rally later in the evening and elsewhere in the city.
"We won't allow Imran Khan to come Karachi if he continues with these baseless allegations," senior MQM member Nabeel Gabol said as protesters chanted anti-Khan slogans.
There was no sign of violence, but the mood of protests in Karachi, Pakistan's biggest city, can turn quickly.
Karachi generates about half of the government's revenue and is home to Pakistan's main port, stock exchange and central bank. Stability in the city is key to the stability of the nuclear-armed country.
The MQM, a secular party, is locked in a battle with various rivals for influence in Karachi, including Pakistan's Taliban movement, which has sought to gain a foothold in various districts on the outskirts of the city in recent years.
The general election handed a landslide victory to opposition leader Nawaz Sharif and his Pakistan Muslim League-Nawaz (PML-N). But Khan's campaign electrified many Pakistanis, pushing the PTI from the margins to Pakistan's third-largest party.
Results from a handful of constituencies across the country are still uncertain amid accusations of vote-rigging. There is re-polling in a few others where security issues prevented voting.
Police said that two gunmen shot Hussain on Saturday outside her home in Defence.
"I hold (MQM leader) Altaf Hussain directly responsible for the murder as he openly threatened PTI workers and leaders through public broadcasts," Khan, recovering in hospital from a fall during campaigning, said.
"I also hold the British government responsible as I had warned them about British citizen Altaf Hussain after his open threats."
Altaf Hussain is accused of murder in Pakistan and leads his party remotely from exile in England. His party is designated a terrorist organization by Canada, a charge it strongly denies.
In recent days, he gave a speech which many Pakistanis felt was an incitement to attack political rivals. British police are investigating whether or not it constituted a hate speech.
"We are in the early stages of the investigation and are assessing the information which has now been brought to our attention," London's Metropolitan Police said in a statement.
Karachi is home to 18 million people. It typically sees about a dozen murders a day, a combination of political killings, attacks by the Pakistan Taliban and sectarian militant groups, and street crime.
(Additional reporting by Nick Macfie in Islamabad and Maria Golovnina in London)