The heady U.S. street celebrations that erupted after the death of Osama bin Laden gave way yesterday 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.

“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.

There was no specific threat cited by federal or local authorities, who said extra patrols at sensitive sites were precautionary measures.

In the Arab world, some mourned bin Laden as a holy warrior and martyr, while others saw him as a “pillar of evil” whose deadly attacks on the United States unleashed a backlash against Muslims across the world.

The U.S.-backed Palestinian Authority welcomed bin Laden’s killing as “good for the cause of peace.” Its rival and prospective power-sharing partner, Islamist Hamas, deplored it.

‘Just a bad memory’

Experts said the killing had little relevance to an Arab world fired by popular revolt against oppressive leaders. “[Osama bin Laden] is just a bad memory,” said Nadim Houry of Human Rights Watch. “The region has moved way beyond that, with massive broad-based upheavals that are game-changers.”