BIRMINGHAM (Agencies) - Three Pakistani nationals were killed here on Wednesday while protecting their community from the rioters, British police said. The trio was struck by a car which mounted a pavement in Dudley Road on Wednesday morning. According to Birmingham police, the men had been drawn into a fight with looters as they defended their properties and businesses from rioters. Police launched a murder inquiry as a friend of the men told BBC they had been part of a group of British Asians protecting their area from looters after attending Ramazan prayers at a mosque. The car swerved toward them. It was cold-blooded murder, the friend said. Two brothers Haroon Hussain, 32, and Shazad Hussain, 30, were pronounced dead at the scene. While the third man identified as Mansoor Ali, 22, died in the hospital. All three slain Pakistanis hailed from Gujar Khan. Police said they had arrested a man and launched a murder inquiry after the incident which happened at around 1:00 am (0000 GMT) as Britains second biggest city suffered from another night of riots. Paramedics said they found around 80 people at the scene after the men were hit by the car. Around 200 people from Birminghams Asian community gathered outside the hospital where the victims were taken and that riot police were also stationed here, the BBC reported. There was no immediate confirmation of those details from police. Prime Minister David Cameron expressed regrets over the death of three Pakistanis and said police were working on the case and killers would soon be arrested. Meanwhile, Pakistani High Commission in London conveyed its concern to the British authorities over the deaths and asked Pakistani community to cooperate with British police for maintaining law and order. Prime Minister Cameron said a fightback was underway Wednesday after four nights of violent riots as he authorised police to use water cannon for the first time in mainland Britain. With Britains worst riots in a generation spreading to the northwest city of Manchester and three Pakistani people being killed while defending their community in Birmingham, central England, Cameron said there was a sickness in society. He said London was quieter overnight after 16,000 police flooded the streets and vigilante groups protected stricken neighbourhoods from gangs who have burned down and raided dozens of shops and homes. We needed a fightback and a fightback is underway, Cameron told a news conference outside 10 Downing Street after the second meeting of Britains COBRA security committee in as many days. We now have in place contingency plans for water cannon to be available at 24 hours notice, Cameron said, adding that police had already been authorised to use plastic baton rounds against rioters. Elsewhere, in Salford, rioters threw bricks at police and set fire to buildings. A BBC cameraman was attacked. Television pictures showed flames leaping from shops and cars, and plumes of thick black smoke billowing across roads. Greater Manchester Police has been faced with extraordinary levels of violence from groups of criminals intent on committing widespread disorder, Assistant Chief Constable Gary Shewan said. These people have nothing to protest against - there is no sense of injustice or any spark that has led to this. It is, pure and simple, acts of criminal behaviour which are the worst I have seen on this scale. In Liverpools Toxteth district, rioters attacked two fire engines and a fire officers car, police said. Earlier, some 200 youths throwing missiles wrecked and looted shops, causing disorder and damage, police said. Police said they had arrested 113 people in Manchester and Salford, and 50 in Liverpool. In Gloucester, in western England, eight fire crews fought a blaze in a large derelict building, cars were set on fire and groups of youths attacked police with rocks and bottles. Cars were burned and stores looted in West Bromwich and Wolverhampton in central England; and in Nottingham a gang of young men set fire to a police station. There were also disturbances in Birmingham and Leicester in the Midlands, and Milton Keynes north of London. In London, commuters hurried home early on Tuesday, shops shut and many shopkeepers boarded their windows. Gangs have ransacked stores, carting off clothes, shoes and electronic goods, torched cars, shops and homes - causing tens of millions of pounds of damage - and taunted the police. Meanwhile, defiant Britons have taken to the streets in their hundreds to defend their communities against rioters but some have paid with their lives and police have warned against vigilante-style justice. From immigrant communities guarding their communities to football supporters chanting England, England, England as they patrol their neighbourhood, many groups have taken matters into their own hands after four nights of looting. Hundreds of Sikhs, some dressed in traditional outfits, gathered outside their gurdwara in Southall, west London, late Tuesday after earlier rumours circulated that it was next on the looters hitlist. The group organised motorcycle patrols and monitored the train station for potential troublemakers, according to an AFP reporter. Around 200 locals in Enfield, the north London borough at the heart of previous attacks, strode through the area to protect their streets, an AFP correspondent said. Amateur video footage released Wednesday showed a group of around 100 men running down an Enfield street chanting England, England, England. The group earlier became involved in an altercation with a youth carrying a hockey stick, but the situation was resolved after a majority of the mob called for calm. A similar number of football fans congregated in the southeast suburb of Eltham, also rumoured to be a likely hot spot. Mainly Turkish shopkeepers in the north London districts of Hackney and Kentish Town sat outside their shops into the early hours, many with makeshift weapons by their side. In the affluent south London district of Clapham - nicknamed Nappy Valley as it is home to large numbers of middle-class young parents - residents reportedly manned a barricade across a main road to keep out rioters on Monday night. In the suburban west London suburb of Ealing a man was critically injured on Monday night after rioters beat him up when he confronted them. The need for vigilante groups on British streets has also raised serious questions about the police and governments ability to handle the situation. But a senior officer with Londons Metropolitan Police, Deputy Assistant Commissioner Steve Kavanagh, warned that the vigilantes were hampering the policing operation. Meanwhile, a father described how he rushed to aid a dying man hit by a car during riots in the English city of Birmingham only to find it was his 21-year-old son. I heard the thud, ran around and I saw three people on the ground, Tariq Jahan told reporters. My instinct was to help the three people. I didnt know who they were, whod been injured. I helped the first man, and somebody from behind told me my son was lying behind me. So I started CPR on my own son. My face was covered in blood, my hands were covered in blood. Police launched a murder inquiry after all three Muslim men died. A 32-year-old man has since been arrested. The men were part of a group of British Asians attempting to protect their area from looters after attending Ramadan prayers at a mosque, a friend of the men told BBC radio. They acted after seeing gangs break into a petrol station and social club, and neighbours being beaten up, Jahan said. Riots spread to Englands second city on Tuesday after three nights of violence in London. Why, why?, Jahan said. I dont understand. We are here defending the community of all the problems that are going on in the country. He was trying to help his community. He said his son, Haroon, a mechanic, was well-liked and well-known in the community. You lose your son, I cant describe to anyone what it feels like to lose your son, he said. (Reporting by Avril Ormsby; Editing by Jodie Ginsberg and Robert Woodward)