British police chiefs on Sunday hit back at Prime Minister David Cameron's plans to enlist a U.S. crime expert after last week's riots, as the conservative leader vowed "zero tolerance" against street violence.
Cameron, criticized by some in his party as being too liberal on crime and punishment, has taken a tough stance after several nights of looting and arson hit cities across England.
"We haven't talked the language of zero tolerance enough, but the message is getting through," Cameron said in an interview in the Sunday Telegraph.
The prime minister, who has suggested the initial police response to the riots was too timid, has enlisted former New York, Los Angeles and Boston police chief William Bratton to advise his coalition on how to tackle street gangs, which he blamed for much of the violence.
But senior police officers, who have criticized the Conservative-led coalition's plans for police cuts, have reacted skeptically to the plan. "I am not sure I want to learn about gangs from an area of America that has 400 of them," Hugh Orde, president of the Association of Chief Police Officers, told the Independent on Sunday.
"It seems to me, if you've got 400 gangs, then you're not being very effective. If you look at the style of policing in the States, and their levels of violence, they are so fundamentally different from here," said Orde, a front runner for the position of head of London's police.
Cameron has dismissed suggestions that political and economic grievances lay behind the violence which killed five people, calling it "criminality pure and simple".
More than 2,800 people have been arrested and courts have worked around the clock and during the weekend to clear a third of those cases.
Two men, aged 17 and 26, were charged late Saturday with the murder of three Muslim men knocked down in Birmingham while trying to protect their communities.
About 20,000 people were due to attend a multi-faith peace march on Sunday in the central England city with the aim of keeping a lid on any potential racial tension.