Streets in London remained largely quiet with heavy police presence after sporadic unrest spread across central and northern England on for a fourth night of violence and rioting. The continuous riots have affected the David Cameron government's image and ability to hold the 2012 London Olympics safely.Unrest was reported in Manchester, Salford, Liverpool, Wolverhampton, Nottingham, Leicester and Birmingham with shops being looted and set on fire. So far 768 people have been arrested and 105 charged in connection with violence in the capital. 16,000 police officers have been deployed in the city to maintain law and order.Scotland Yard said a 26-year-old man shot in a car during riots in Croydon died in hospital, becoming the second victim after 29-year-old Mark Duggan, whose death in police firing on Thursday had sparked the riots. The Police maintained that, London is witnessing a wave of copycat criminal activity since the initial disturbance.Sporadic violence broke out last night in several cities. Canning Circus police station in central Nottingham was firebombed by a male gang last night. In Leicester, a group of up to 100 youths attacked shops and threw items at police.In Liverpool, Merseyside Police arrested 46 rioters. Around 111 police officers suffered injuries after being attacked by rioters wielding bottles, planks, bricks and even driving cars at them. The National Express coaches have suspended services to Wolverhampton, Birmingham and Manchester where people are instead, being dropped off at either Manchester Airport, Oldham or Stockport.Prime Minister David Cameron had yesterday called for an emergency day-long session of Parliament tomorrow to discuss the situation and to defuse the crisis of rioting on the streets across England.