(Updates with official announcement, new quotes)
By Jill Serjeant
LOS ANGELES, Feb 8 (Reuters) - Los Angeles police named 11 of the city's worst street gangs on Thursday and said they would put some members on the FBI's most wanted list to crack down in what has been called the "gang capital of America."
A "gang czar" will be appointed and police officers redeployed to gang-infested areas in a much-anticipated offensive to stem an alarming increase in drive-by shootings and murders in a city which has an estimated 720 gangs with some 40,000 members.
"We are taking a new approach to gangs this year," Los Angeles Chief of Police William Bratton told a news conference.
"Eleven gangs and their 900 members committed over 1,700 violent crimes last year. That's six percent of all the violent crime in the city. It makes sense to focus our very limited resources on these criminals."
The strategy of publicly naming specific gangs and their members is a break with past police policy which held that doing so would give members much-desired notoriety.
But the new approach "challenges these menaces by exposing their corrosive behavior to the scrutiny of a more informed and confident community," the plan unveiled by Bratton and Mayor Antonio Villaraigosa said.
Six of the targeted gangs are predominantly Latino and five are predominantly black.
The measures follow a 14 percent increase in violent gang-related crime in 2006 despite a citywide decrease in crime over the past five years. Police say street gangs were responsible for 56 percent of the city's 478 murders in 2006.
"Los Angeles county and city is, unfortunately, the gang capital of America," Los Angeles County Sheriff Lee Baca told reporters this week.
One of the named gangs is the notorious Mara Salvatrucha, or MS-13, which formed in Los Angeles in the 1980s and 1990s to protect early immigrants escaping civil war in El Salvador.
The gang has some 50,000 members in at least six nations.
Some gang experts said they were disappointed with the plan, which follows an independent report calling for a comprehensive approach including more projects to give disaffected teens jobs and alternatives to gang life.
Malcolm Klein, sociology professor at the University of Southern California, said it was a mistake to publicly name gangs.
"These kids will walk with clippings in their pockets. Kids join gangs for identity, status, reputation and a sense of excitement. If you declare war on gangs, you are feeding exactly what they joined for in the first place," Klein said in a telephone interview.
Villaraigosa, who grew up on the city's tough East side, said on Thursday he would announce at a later date citywide programs to discourage youths from joining gangs.
"We will aggressively enforce the law, but we must be equally aggressive in providing our kids with opportunities and alternatives and hope for the future," he told reporters.