Britain needs to tackle deep-seated social problems following riots and looting in English cities this week, the center-right government said on Saturday, and a U.S. street crime expert it has brought in said arrests alone would not solve the problem. "There are communities that have just been left behind by the rest of the country. There are communities that are cut-off from the economic life-blood of the rest of the country," Finance Minister George Osborne said. Prime Minister David Cameron, criticized by some in his Conservative party as being too liberal on crime and punishment, has taken a hard line on rioting in statements this week after returning from his summer holiday and recalling parliament. He has also come under attack for austerity measures his government is introducing to tackle a huge debt burden.