By David Clarke

LONDON, Feb 18 (Reuters) British Prime Minister Tony Blair today backed tougher laws aimed at cracking down on gun crime after a spate of teenage murders in the capital that has sparked much soul-searching about the state of British society.

The fatal shootings of three youths this month in south London have generated a rapid political response and led to heated debate about whether the killings reflect a general malaise in the nation at large.

Blair said while gun crime in Britain, and London specifically, had fallen over the past year, tougher sentences for youngsters found carrying guns would help police clamp down on gangs.

''Is it a general state of British society, British young people? I think it isn't. It is about a specific problem, within a specific criminal culture to do with guns and gangs,'' Blair told BBC television.

Fatal shootings have been falling in Britain.

According to Home Office crime data, 97 people were killed by shooting in 2001/02, 68 in 2003/05, 75 in 2004/05 and 50 in 2005/06, the lowest total for seven years.

Overall gun-related crime, including air weapons, fell 6 percent in 2005/06 from the previous period.

But the fact that all three of those killed this month in the sprawling capital were under 17 has shocked the country.

''There is a particular problem which is that the minimum 5-year sentence that we have introduced for illegal possession of a firearm does not apply to those under the age of 21 and we've got to lower that age ... down to the age of 17,'' Blair said.

Billy Cox, 15, was shot dead at his home in Clapham in south London last week. That murder followed the shooting of schoolboy Michael Dosunmu, 15, in his bedroom in nearby Peckham on Feb. 6.

Three days earlier, James Smartt-Ford, 16, was gunned down at Streatham ice rink, also in south London.

London's population stood at 7.5 million in mid-2005, according to Britain's Office of National Statistics, COMPLEX ISSUES Blair said gang membership should be taken into account when offenders are sentenced and that those prepared to give evidence against gangs should be given proper protection.

Home Secretary (Interior Minister) John Reid said last week he had asked his ministry to look at ways of strengthening legislation and sentencing for gun offenders.

The main opposition Conservative Party welcomed Blair's call for tougher sentences but said it was knee-jerk government reaction to bad headlines and the underlying causes within British society needed to be addressed.

''The issue here is the circumstances they grow up in, the broken families -- and that's not confined to any one sector of society -- and the massively rife drug culture,'' said Conservative home affairs spokesman David Davis.

''That isn't just black youngsters, it's black, brown, white, Asian, Caribbean, you name it,'' he told Sky television. ''The problems have been growing for a decade ... and they've only reacted when we've had a headline.'' REUTERS PDM HT1900