Karachi:
The Hospital staff says 45 people have been killed and 93 others wounded in a wave of violence which has brought much of Pakistan's commercial capital Karachi to a standstill.
Dozens of vehicles and shops were set on fire as security forces struggled to gain control. Schools and colleges were ordered by the government on Tuesday to close.
The violence came after Raza Haider was shot dead along with his bodyguard in a mosque in the city while preparing to offer prayers on Monday.
Local government officials said at least 10 people were arrested, and that police and Army Rangers were dispatched throughout the city to impose order. But gunfire could still be heard Tuesday morning.
The southern city of more than 16 (m) million has a history of political, ethnic and religious violence, and has long been a hide-out for al-Qaida and Taliban militants. Its stability is considered paramount for Pakistan, because it is the country's main commercial hub.
Haider was a member of the Muttahida Qaumi Movement (MQM), the political party that runs the city and represents mainly descendants of migrants from India who settled in Pakistan when it was created in 1947.
The MQM's main nemesis is the Awami National Party, a secular nationalist party whose main power centre is Pakistan's Northwest and whose base is the ethnic Pashtun community.