In protest against the killing, Congress workers put up a blockade at Delhi Road at 7 am on Wednesday.
When a police team went there, the protesters started pelting stones to them injuring four policemen and set fire to a police jeep, Roychowdhury said.
The police used batons to disperse the mob that also left five persons injured, he said.
The SP said efforts were on to arrest the killers of Paswan and the situation is now under control.