London: Prime Minister David Cameron said a "fightback" was under way Wednesday after four nights of violent riots, as he authorised police to use water cannon for the first time on the mainland.
After the worst riots in a generation spread to Manchester and three Asian men were hit and killed by a car while defending their community in Birmingham, Cameron said there was a "sickness" in British 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 under way," Cameron told a news conference outside 10 Downing Street after the second meeting of the 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.
Water cannon have only previously been used in Northern Ireland to tackle sectarian tensions between the Protestant and Roman Catholic communities.
The violence has raised questions about security ahead of the 2012 London Olympic Games, and it prompted the cancellation of Wednesday`s football friendly between England and the Netherlands at Wembley Stadium.
Cameron`s tough new line comes after he flew back from holiday in Tuscany on Tuesday to take charge of the biggest challenge to the coalition government since it came to power in May last year.
More than 1,100 people have been arrested across the country for violence, disorder and looting since the riots erupted on Saturday in Tottenham after the fatal shooting of Mark Duggan by police two days earlier.
The prime minister dismissed "phoney concerns about human rights" over the issuing by police of photos of some of the suspected rioters. He also called for all those convicted over the disorder to be jailed.
Manchester and the Midlands bore the brunt of Tuesday night`s violence.
In Birmingham, police said they had arrested a man and launched a murder inquiry after an incident in which three Asian men died when they were hit by a speeding car.
Witnesses said the men who died had just come out of a mosque and were protecting their neighbourhood shops from rioters.
"They lost their lives for other people, doing the job of the police," Mohammed Shakiel said outside the hospital where the men were taken, prompting around 200 people to gather in support.
Tariq Jahan, whose 21-year-old son Haroon Jahan was one of those killed, urged locals not to take revenge and called for the law to be allowed to take its course.
"I don`t blame the government, I don`t blame the police, I don`t blame nobody," he said. "I`m a Muslim, I believe in divine fate and destiny, and it was his destiny and his fate, and now he`s gone."
The government has blamed "opportunistic" criminals for the unrest, but the opposition says cuts to social services and the failure to deal with underlying social problems has contributed to the riots, which have mainly been in deprived areas.
In Manchester masked gangs set fire to a girls` fashion store and smashed the glass entrance of the Arndale Centre, the main shopping mall, allowing hundreds of youths to run off with armfuls of clothes and shoes.
Assistant Chief Constable Garry Shewan of Greater Manchester Police, who joined the force after moving to the city in 1981, called the scenes "senseless violence and senseless criminality on a scale I have never witnessed before."
Elsewhere 200 rioters pelting police with missiles in the Toxteth area of Liverpool, which was rocked by huge riots in 1981.
Hooded rioters also set fire to buildings in West Bromwich and Wolverhampton and a police station in nearby Nottingham was firebombed, while there was also trouble in Gloucester.
The only other fatality of the riots so far was a man found with a gunshot wound to the head in a car in the south London suburb of Croydon.