Security forces on high alert in Karachi after arrest of London-based politician Altaf Hussain

MQM supporters protest in Karachi after the arrest of Altaf Hussain in London (Getty Images)

Security forces in Karachi have been placed on heightened alert after police in Britain arrested a powerful London-based Pakistani politician as part of an investigation into money laundering. The arrest sparked panic among many in Karachi, fearful of a violence backlash from the politician’s supporters.

Officers from the Metropolitan Police confirmed they had arrested Altaf Hussain, head of the Muttahida Qaumi Movement (MQM), at his home in north-west London where he has lived for more than 20 years. The 60-year-old was later taken to hospital for a prearranged check-up.

The MQM, which was established in 1984 to represent Urdu-speaking Muslims who originally travelled from India to Pakistan after Partition, has a power base in Karachi and has been a major player in local, regional and national politics in Pakistan.

Yet in Karachi, like most other parties, it has over the years been blamed for seemingly endless cycles of violence and killing between gangs linked to various political factions. The MQM has always denied the allegations, claiming it is peaceful and stressing its secular nature.

News of Mr Hussain’s arrest triggered chaos in parts of the city as people rushed home in an attempt to avoid any violent backlash. Roads were jammed and police struggled to deal with traffic as shops, markets and businesses closed early and sent their staff home. The British consulate in the city of 25 million people was temporarily closed.

On Tuesday night, as thousands of supporters held sit-down protests, leaders of the MQM appealed for calm and restraint among their workers. There were reports of sporadic burning of vehicles but the party claimed its members were not responsible.

In a statement issued by Nadeem Nusrat, a member of the MQM’s central committee, the party said Mr Hussain was loved and adored by millions of people who were now concerned about his welfare. “We also feel and share those sentiments and appeal to all people to control their sentiments and maintain peace at all costs,” it said.

Mr Nusrat later added: “This ongoing investigation is part of due process and the party is prepared to assist the British police with all their enquiries as neither Altaf Hussain nor the party have anything to hide.”

Mr Hussain fled Karachi in 1992. His supporters say it was no longer safe for him in the city while others say he was the subject of investigations by the police.

For many years he was able to maintain an iron grip on the party and addressed large gatherings by telephone. But in recent years, with Mr Hussain suffering health problems, there has been evidence of disagreement and even fissures within the senior leadership. A year ago, the central committee was dissolved and a new one formed after Mr Hussain had publicly criticised it,

In London, the MQM has also been part of an investigation by police into the stabbing to death of another senior party member, Imran Farooq, who was murdered on a street in Edgeware in 2010. He had also been living in self-imposed exile.

Scotland Yard last week released the names of two Pakistani men who they said were suspects for the murder of Dr Farooq. He was found dead outside his London home in what police believe was a politically motivated killing after rumours emerged he was planning to split from the party.

The murder, which police said was carefully planned and involved a number of people, saw the politician stabbed multiple times with a kitchen knife and battered with a brick.

Police want to interview the two men, Pakistani nationals aged 29 and 34, who were in London at the time of the murder and left Britain that night. They had registered to study at an east London college having come into the country on student visas.

Scotland Yard on Tuesday declined to name Mr Hussain and would only say that a 60-year-old had been arrested on suspicion of money laundering. The home was being searched was in north-west London.

Imtiaz Gul, an Islamabad-based analyst and director of the Centre for Research and Security Studies, said it was difficult to assess what impact the arrest of Mr Hussain would have until any legal process was completed. “The party is urging its supporters to remain calm” he said. “If he is convicted, then we might see violence in Karachi.”