Within minutes of President Obama's announcement Sunday night that U.S. forces had killed terrorist leader Osama bin Laden, police in Rockland County were put on alert and stepped up efforts to safeguard key locations and facilities.

Rockland County Sheriff James Kralik said police throughout the county and the New York City metropolitan area remain on alert in case of any possible acts of retaliation for the killing of bin Laden, the mastermind of the Sept. 11, 2001 terror attacks on the United States.

Immediatly after the President's late-night speech, Kralik said he held over a Sheriff's Department patrol shift to assist in safeguarding key locations, including:

— Gathering spots
— Transportation hubs
— Local infrastructure
— Schools
— Religious institutions

Kralik said emergency officials in Rockland also has special gear ready to detect radiological threats that could come with weapons possibly transported by vehicle on area roadways.

"This is absolutely no time to be complacent," Kralik said. "This should be a time when we have to stop with the complacency and see what's going on around us."

Kralik and Rockland County District Attorney Thomas Zugibe on Monday urged members of the public to be on alert for anything unusual — including things such as unattended packages in public places — and to call police if they are concerned about a possible danger to the community.

"If you see something, say something," Kralik said. "Even if it turns out to be nothing, we'd rather people called us if they think there is something suspicious."

In the wake of bin Laden's death, both Kralik and Zugibe said they were pleased that U.S. forces had tracked down and killed bin Laden in a mansion hideout in Pakistan. However, both law enforcement officials said they are concerned that public celebration in the U.S. of bid Laden's death could antagonize bin Laden supporters and incite acts of retaliation against Americans or U.S. troops.

"I think we are all equally jubilant about the death of bin Laden, but as we saw Americans cheering we also saw that as an ignition switch," Kralik said.

Zugibe said he fears that scenes on television of Americans cheering in Times Square and in front of the White House on Sunday night could have created new problems for the United States.

"This is a dangerous time," Zugibe said. "We will see attempts at retaliation. People have to be very careful and be alert."

Kralik said that he and law enforcement officials from Rockland, Orange and Sullivan counties spoke to update each other on security efforts, and that calls was followed by a statewide alert to police in New York to heighten security measures in the wake of bin Laden's death.