(CNN) -- Businesses in parts of Pakistan's most populous city shut down Thursday, amid uncertainty and tension tied to the recent arrest, by London police, of the leader of one of the country's most powerful regional parties.
Video from CNN affiliate Geo TV showed shops that had closed or were in the process of closing in Nazimabad, Liaquatabad and other parts of Karachi.
"There are elements that are forcing people to shut down their shops and businesses," local trade society president Tajir Ittehad Ateeq Mir told reporters.
Such shutdowns have been connected to the arrest in London of Altaf Hussain, head of Pakistan's Mutahida Qaumi Movement, on Tuesday morning.
Metropolitan Police said they arrested a 60-year-old man, who they did not name, at a home in northwest London on suspicion of money laundering. But officials in Pakistan subsequently identified him as Hussain.
Members of the Mutahida Qaumi Movement, which is known as MQM, have staged protests, including sit-ins, since that arrest. But party officials insist they have nothing to do with shutting down businesses, accusing others of manipulating the situation.
"The MQM Central Coordination Committee has strongly condemned the miscreant elements who are involved in closing down businesses and aerial firing in some areas of Karachi and Hyderabad," the party said in a press release. "It seems that some elements want to deteriorate the situation deliberately so that MQM can be blamed."
The party appealed for people to go about their business as usual and remain peaceful, with senior leader Haider Abbas Rizvi telling reporters that Hussain himself has related that he doesn't want supporters to take the law into their own hands.
MQM is the fourth-largest party in Pakistan's parliament, holding 25 out of 446 seats, though it is a greater force in Sindh province, including Karachi. It is led by Hussain from his base in the United Kingdom, where he sought asylum in 1991 because of an attempt on his life, his party has previously said.
Hussain -- who had been ill and was preparing to leave his home to get checked at a hospital when he was arrested, according to MQM Senior Deputy Gov. Nadeem Nusrat -- was still in a hospital Thursday under police watch.
Pakistan's High Commissioner to the UK Imran Mirza has visited Hussain at the hospital and given him documentation -- including a Pakistani passport -- so that he and other Pakistani officials could continue to have access to him, said Pakistani Information Minister Pervez Rasheed.
Some protests called by MQM after Hussain's arrest turned violent, something that the party condemned.
Thursday saw more bloodshed in Karachi. A bomb placed on a motorcycle exploded outside of a mosque, killing one person and injuring five others, according to Ahmed Chinoy, the chief of the citizen's police liaison committee told CNN.
There is no indication whether that attack had anything to do with MQM or Hussain's arrest.
CNN's Saima Mohsin contributed to this report.