Two convicted murderers who used power tools to escape from prison near the Canadian border must have taken days to cut through steel walls and pipes and break through the bricks, Gov. Andrew Cuomo said Sunday as a $100,000 reward was posted for information leading to their capture.

Quebec-based RCMP officers are advising anybody who comes across a pair of escaped murders to call police and avoid contact.

RCMP officials told CTV Montreal Sunday that they have no information suggesting that the duo had escaped into Canada but have taken precautions nonetheless, spreading the word to various law enforcement agencies and keeping a lookout for the men.

On Saturday two convicted murderers used power tools to cut through steel and shimmied through a steam pipe to escape from a maximum-security prison near the Canadian border, leaving behind a taunting note urging authorities to "Have a nice day."

About 250 police officers are actively searching for the duo and New York state police are studying all possibilities. They acknowledge that the duo might have had help and fled the state in a car or split up and continued on foot.

The cunning escape from an upstate New York prison on Saturday had hundreds of local, state and federal law enforcement officers searching for one of the deputy's killers and another man imprisoned for dismembering his boss.

Richard Matt and David Sweat staged what Gov. Andrew Cuomo called "a really elaborate, sophisticated operation" that ended at a manhole cover blocks away from the prison.

The men had filled their beds inside the Clinton Correctional Facility with clothes to appear as though they were sleeping, cut into steel steam pipes and shimmied out of the prison. On one pipe cut in the escape, investigators found a note with a crude Asian caricature along with the words, "Have a nice day."

Sweat, 34, is serving a sentence of life without parole after he was convicted of first-degree murder for killing a sheriff's deputy in Broome County, New York, on July 4, 2002. Matt, 48, is serving a sentence of 25 years to life for the kidnapping, dismemberment and killing of his former boss in 1997.

Steven Tarsia, brother of Deputy Kevin Tarsia, said finding out his brother's killer had escaped "turns your world upside-down all over again."

Prison escape

New York Gov. Cuomo looks at the area where prisoners used power tools to free themselves from their cells in Dannemora, N.Y. (Darren McGee / New York State Governor's Office)

He said just the other day, he had been trying to remember the names of the men responsible for his brother's death, and "I couldn't remember their names.

"All of a sudden, I remember them again," he said.

Tarsia told The Associated Press on Sunday he couldn't imagine how the men could have gotten power tools and escaped without help, but "I don't know why anybody would help them."

Cuomo said it was impossible to believe nobody heard the noise of the tools.

"They were heard, they had to be heard," Cuomo told ABC's "Good Morning America" on Sunday.

Prison escape

This photo shows the area where two convicted murderers used power tools to cut through steel pipes, and leave a note, at a maximum-security prison in Dannemora, NY. (Darren McGee / New York State Governor's Office)

Roadblocks were set up in the area around the village of Dannemora, which is about 32 kilometres from the Canadian border, and bloodhounds and helicopters were being used to track down the men, officials said.

The escape also prompted the Ontario Provincial Police to issue an internal alert to its officers.

Due to the close proximity of the prison to the Canadian border, OPP officers are patrolling with "heightened vigilance," said Sgt. Peter Leon, the force's provincial media relations co-ordinator.

However, Leon stressed that there was no indication the two fugitives had crossed the border into Ontario, or were even headed that way. He said the primary purpose of the alert was to keep officers safe.

Police in Quebec said they had not received any special alerts or instructions regarding the escaped inmates.

Beth Nichols, an employee of the Dunkin' Donuts across the street from the prison and a few hundred yards from the manhole where authorities said the men emerged, said the situation was "nerve-wracking."

She said one employee had a panic attack Saturday after being told about the prisoner breakout. "She got really scared, and she cried," Nichols said. The employee lives a walk away on the same road, but authorities would not immediately allow her to enter her home; her mother picked her up.

Dannemora occupies about 2 1/2 square kilometres within the northern reaches of the Adirondack Forest Preserve and is surrounded by forest and farmland. The stark white perimeter wall of the prison, topped with guard towers, borders a main street in the village's business district.

Cuomo on Saturday called described the two men as extremely dangerous. He asked the public to notify the police should they encounter the men.

"It's very important that we locate these individuals," he said. "They are dangerous and we want to make sure they don't inflict any more pain and any more harm on New Yorkers."

The two men's adjoining cells were empty during a morning check, said Anthony Annucci, the acting state corrections commissioner.

"A search revealed that there was a hole cut out of the back of the cell through which these inmates escaped," Annucci said. "They went onto a catwalk which is about six stories high. We estimate they climbed down and had power tools and were able to get out to this facility through tunnels, cutting away at several spots."

Investigators were probing how the men acquired the tools -- and if any were missing from contractors at the prison.

Officials said it was the first escape from the maximum-security portion of the prison, which was built in 1865.

Sweat is white, 5 feet 11 inches, with brown hair and green eyes and weighs 165 pounds, police said. He has tattoos on his left bicep and his right fingers.

Matt is white, 6 feet tall, with black hair and hazel eyes, according to police. He weighs 210 pounds and has tattoos including "Mexico Forever" on his back, a heart on his chest and left shoulder and a Marine Corps insignia on his right shoulder.

Sweat and another man fired 15 rounds into Deputy Tarsia in 2002 shortly after using a pickup truck to break into a Pennsylvania woman's house, stealing rifles and handguns, authorities have said.

And nearly a decade after the 1997 kidnapping, murder and dismemberment of his former boss, William Rickerson, in upstate New York, Matt was returned to the U.S. from Mexico where he had fled to and, later, was arrested for fatally stabbing another American outside a bar in a robbery attempt. He was convicted in 2008 of Rickerson's death.

-With a file from The Associated Press