Vehicles and buildings were set on fire on Wednesday
Paramilitary troops are out in force in the Pakistani city of Karachi, with tension high a day after ethnic clashes killed at least 32 people.
There have been a number of fresh incidents of violence reported, including shots fired at the funerals of some of the victims.
The clashes are said to be between Urdu-speakers and ethnic Pashtuns.
Separately, President Asif Ali Zardari called for national unity in tackling militants in the restive north-west.
Pakistani troops this week launched operations in the Lower Dir and Buner regions to remove Taleban militants who had spread there from their stronghold in Swat.
'Shoot on sight'
"We have compiled a list of those killed and injured from last night's violence," Karachi Police Surgeon Liaquat Memon told the BBC.
The clashes were said to be between Urdu-speakers and ethnic Pashtuns
"According to the list, 32 people have died and 50 have been injured during the violence. The death toll includes those brought in injured who later expired in the hospitals.
"The data covers all the major hospitals in the city."
A spokesman from the Pakistan Rangers paramilitary force told Reuters news agency: "We have heavy deployment of troops across the city, and they have been told to go to any extent to control the situation, including shoot on sight orders for miscreants."
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