"We demand the armed forces take over the city, restore law and order and ensure safety to innocent people's lives," Khalid Tawab, vice president of the Federation of Pakistan Chambers of Commerce and Industry (FPCCI), told AFP.
"Business activity has been disrupted because of incessant killing. People don't want to go to market because of risk to life," he said.
Ethnic and criminal violence blamed on gangs has killed 101 people in the last week, the latest bout in the worst criminal and ethnic violence to hit Pakistan's largest city and financial capital in 16 years.
"At least nine people were killed since Monday evening, so far 101 people have been killed since Wednesday morning," a senior security official told AFP on condition of anonymity because he was not authorised to speak to the media.
Security officials said they had found the bodies of victims who had been kidnapped and tortured, stuffed into sacks and thrown on the streets with notes warning of more violence.
A government official working in the health department confirmed the casualties.
The violence has been linked to ethnic tensions rival political groups.
On Tuesday, markets were closed, streets deserted and attendance at offices thin after the MQM called for a "day of mourning" against the killings.
Prime Minister Yousuf Raza Gilani on Monday flew to Karachi and asked the provincial government to restore peace as quickly as possible.
Sharjeel Memon, Sindh provincial information minister, said a "surgical operation" was planned to end the violence.
However, the PPP insists that civilian authorities are capable of controlling the situation.
But members of other political parties are calling for army intervention.
"We want to see law and order in Karachi improve. Anyone, including the army, who can get results and improve the situation should take control," Wasay Jaleel, a spokesman for MQM, told AFP.
"We demand the army across the board to restore peace here," ANP's provincial chief Shahi Syed told AFP on Tuesday.
People on the streets also expressed dissatisfaction with the ability of the police and the paramilitaries, technically answerable to the interior ministry, to control the situation.
"The armed forces should be deployed in Karachi, because police and paramilitaries have failed to save our lives," said Khalid Ali, 45, a shopkeeper in the main downtown market area that has seen some violence.
"We feel no enthusiasm for Eid. Please, soldiers take the city in their hands and return smiles to our children," Noshaba Hameed, a 37-year old schoolteacher, told AFP by telephone.
Copyright AFP (Agence France-Presse), 2011