By Marty Graham
SAN DIEGO, July 2 (Reuters) - U.S. immigration officials clamped a lid on Wednesday on further plans for handling throngs of Central Americans caught sneaking into the United States, a day after protesters blocked busloads of migrant families sent to a processing center in California.
The immigrant children and their parents are part of a wave of families and unaccompanied minors fleeing strife-torn Guatemala, El Salvador and Honduras and streaming by the thousands over the U.S.-Mexico border via human smuggling rings.
Most have shown up in Texas, overwhelming detention and processing facilities there and leading U.S. immigration authorities to set up overflow sites in California to help screen and manage the influx.
Immigration officials said most of the families headed for California were likely to be released under limited supervision to await deportation proceedings, and would likely be placed with relatives or friends in other cities or stay in temporary housing provided by charity groups.
Those arrangements sparked an outcry in Murrieta, California, north of San Diego, where an initial batch of immigrants were due to be processed at a Border Patrol station in town. The mayor, Alan Long, raised concerns about public safety and potential strains on local resources.
The first group of roughly 140 adults and children, all families, were flown from Texas by plane on Tuesday to San Diego and then bused north to Murrieta.
But an angry crowd of about 150 protesters shouting, "Go home" and "We don't want you here," ignored police orders to disperse as they filled a street near the facility to block the caravan, forcing the buses to turn around.
The passengers ended up being bused to another Border Patrol station in San Diego for processing there.
While Mayor Long said earlier he had been advised by U.S. officials to expect another group of about 140 immigrants every three days for several weeks, it remained unclear after Tuesday's confrontation whether plans would be altered.
City manager spokeswoman Kim Davidson said municipal officials have received no word on what will happen next.
"Out of an abundance of caution and in light of the incident yesterday, we're not providing any additional information ... about next steps or contingency plans," Immigration and Customs Enforcement agency spokeswoman Virginia Kice said. "The priority is to do everything we can for the safety of our personnel and the migrants entrusted to us."
She said immigration authorities were being especially careful to avoid disclosing the whereabouts of the detainees "so that mobs can't go down and root out those people."
Border Patrol spokesman Paul Carr said undocumented Central American families will continue to be sent to Southern California for processing. "I have not been told that there will be any deviation from the plan," he said.
(Writing and additional reporting from Los Angeles by Steve Gorman; Editing by Sandra Maler)