Death toll rose to 55 in the current wave of violence sparked by the murder of a provincial parliamentarian in the southern Pakistani port city of Karachi as police claimed to arrest 68 suspected perpetrators, Pakistani Interior Minister said on Tuesday night.

A policeman asked residents to stay in their homes after supporters of Muttahida Qaumi Movement (MQM) torched a bus early Tuesday morning in protest of the killing of a member of party in Karachi August 3, 2010. [Chinadaily.com.cn? via Agencies]

Raza Haider, a member of Sindh province assembly from the Muttahida Qaumi Movement (MQM), was shot dead along with his bodyguard on Monday when he reached a mosque to attend a funeral of one of his relatives.

His murder triggered riots in Karachi on Monday evening, in which 55 people were killed and over 200 injured, dozens of vehicles, shops and petrol pumps were set on fire.

The MQM party has announced a three-day mourning for Haider and demanded quick arrest of those behind the murder.

Interior Minister Rehman Malik told the National Assembly about the arrest of the three terrorists allegedly involved in the planning of the murder.

"Shakeel Barni, an arrested activist of a defunct organization, said that they had designed to murder three leaders including Haider and carry out two suicide attacks in the funeral," Malik told media outside the parliament.

Barni admitted that he had links with Taliban in South Waziristan who are guiding and funding them to destabilize the city with such killing activities," Malik added.

Meanwhile, Pakistani rangers and police have arrested another 65 suspects involved in the riots. Paramilitary rangers and police are patrolling main roads to avoid further violence.

As the biggest city in Pakistan, Karachi has a long history of ethnic and sectarian violence. Police said that over 700 people have been killed in Karachi in the target killing and subsequent violence since January this year.