Authorities say that two convicted killers who are serving life sentences have broke out of a maximum security prison in upstate NY.

The two men—Richard Matt, 48, and David Sweat, 34—were unaccounted for during a 5:30 a.m. bed check at the Clinton Correctional Facility in Dannemora. Police say both men are considered to be a danger to the public: "If located DO NOT approach them. Contact 911 or the New York State Police immediately at (518) 563-3761."

Sweat is serving a life sentence without parole following his conviction for first-degree murder of a Broome County sheriff's deputy in 2002. Matt is serving a sentence of 25 years to life following his conviction for kidnapped a man and beating him to death in 1997 in Niagara County.

New York Gov. Andrew Cuomo has cancelled his appearance at the Belmont Stakes in order to attend a briefing about the manhunt and hold a news conference later this afternoon.

Update: During his press conference, Cuomo revealed just how the inmates made their escape. They apparently had plumbed through tunnels and had drilled holes in their cells. They left dummies with sweatshirt hoodies in their beds "so it would appear they were sleeping during walk throughs every two hours."

"By definition, it was an extraordinary act," Cuomo said. Investigators are trying to determine how the inmates got the power tools to drill through walls. "These are not people to be trifled with," Cuomo added.