LAS VEGAS (AP) " Tens of thousands of revelers will ring in the new year in Las Vegas under the close eye of law enforcement just three months after the deadliest mass shooting in modern U.S. history.

Tourism officials expect about 330,000 people to come to Las Vegas for the festivities that are anchored by a roughly eight-minute firework display at the top of seven of the destination's casino-hotels.

Inside properties across Sin City, acts including Bruno Mars, Britney Spears, Celine Dion and Foo Fighters will keep celebrants entertained before and after midnight.

The Las Vegas Metropolitan Police Department will have every officer working Sunday, while the Nevada National Guard is activating about 350 soldiers and airmen.

The federal government is also sending dozens of personnel to assist with intelligence and other efforts.