WASHINGTON (Reuters) - The heady U.S. street celebrations that erupted after the death of Osama bin Laden gave way on Monday to stepped up security amid fears of revenge from the worldwide militant networks he inspired.
Thousands of cheering, flag-waving people gathered at the White House and on the streets of New York City overnight to rejoice in the killing of the al Qaeda leader responsible for the deaths of nearly 3,000 people in hijacked plane attacks on both cities nearly a decade ago.
By daybreak, police had increased security in New York, Washington, Los Angeles, Boston and Chicago in the wake of bin Laden's killing by U.S. forces at a fortified compound north of Islamabad, Pakistan.
Public enemy No. 1 was gone, but it was clear bin Laden's legacy -- Islamic militant networks around the world -- remained.
"Insofar as the bigger picture goes, he is yesterday's man. The global jihad rages on," said Pamela Geller, a conservative activist who led protests against a mosque planned near the World Trade Center site.
"I don't think we're safer," said Evonne McKee, 56, a grant-writing consultant from Mount Dora, Florida. "The hate for America didn't go away because he's gone away."
New York's Times Square was even more heavily guarded than usual, with multiple police cars parked on every corner and uniformed officers patrolling the square in pairs. A police helicopter hovered overhead and police set up a mobile watchtower.
There was no specific threat cited by federal or local authorities, who said extra patrols or increased monitoring of sensitive sites were precautionary measures.
In Washington, U.S. homeland security officials were at a "heightened state of vigilance" for possible retaliatory attacks, Homeland Security Secretary Janet Napolitano said.
The capital's transit authorities stepped up patrols by uniformed officers on buses and subways and an extra fence was put up around the White House.
Security also was tightened at U.S. military and air force bases in the southern United States, including the MacDill Air Force Base in Tampa, Florida, headquarters of both the U.S. Central Command and the U.S. Special Operations Command.
Many welcomed the extra vigilance.
"I think we ought to be really on our toes because I'm sure they're thinking of retaliation. They have to be," said Orlando retiree Chuck Hagan.
At the Guantanamo Bay U.S. naval base, some prisoners in the detention camp created to house hundreds al Qaeda-linked suspects after the September 11 attacks were watching television when news broke with word of Osama bin Laden's death.
Air Force Lieutenant Colonel Don Langley, the camp spokesman, said there was no unusual reaction from the remaining 172 prisoners or their guards.
"We're continuing with business as usual. This is not the end of the story for us," he said.
In Boston, the origin of both planes that brought down the World Trade Center, young people rushed onto the streets in glee as news of bin Laden's death spread during the night.
But for those who lost family members in the attacks, the news was bittersweet.
"For some of us, it takes us right back to September 11, 2001," said Christie Coombs, 50, whose husband, Jeff, was killed on American Airlines Flight 11, one of the two airliners that flew into the twin towers.
Celebrations continued on Monday at Biloxi beach on South Mississippi's Gulf Coast, where about 100 people were holding waving American flags at the traffic that went by. Drivers honked their horns and there were shouts of "Go USA!"
At New York's Ground Zero, dozens of uniformed officers stood guard around what is today a large construction site for four new skyscrapers and a memorial. A crowd of thousands that had gathered overnight had dissipated, leaving more police and reporters than celebrators.
"Both my husband and I feel that jubilation is not called for, it's inappropriate. As far as we're concerned, a chapter is closed but the story is far from over," said Diane Horning, whose son Matthew was killed in the attacks.
"It should be a somber occasion. I don't think we should be dancing in the streets. People danced in the streets when my son died."
Reporting by Basil Katz, Edith Honan, Bernd Debusmann Jr., Jeremy Pelofsky, Patricia Zengerle, Ros Krasny, Jane Sutton, Leigh Coleman, Barbara Liston, Robert Green, Tom Brown and Andy Stern; Writing by Doina Chiacu; Editing by Sandra Maler