NEW YORK (AFP) - A manhunt for two convicted killers on the run from a maximum security US prison narrowed Tuesday to a small town where reports suggested the fugitives may have been cornered.

Richard Matt, 49, and David Sweat, 35, whom officials have called violent and vicious, used power tools to cut through walls at the Clinton Correctional Facility in the small New York town of Dannemora on Saturday.

Law enforcement alerted authorities in Canada and Mexico in case they fled the country, but on Tuesday the search appeared to focus on the town of Willsboro, around 40 miles (60 kilometers) south of the jail.

US media said there was a possible sighting of the two men on foot. "The police reacted to it immediately," the Willsboro town supervisor Shaun Gillilland said, according to The New York Times. New York state police refused to comment.

The New York Daily News said several busloads of heavily armed corrections officers and police arrived in Willsboro, and were stopping all traffic in and out of the town. "There are police everywhere now," resident Richard House, 62, was quoted as saying by the Daily News.

Matt, six feet tall with multiple tattoos, was serving a 25-year to life sentence for the 1997 kidnapping and dismembering of his former boss, 76-year-old William Rickerson, in a horrifying 27-hour ordeal.

Matt reportedly hit his victim, bound him with duct tape and threw him into the trunk of a car. He then beat and assaulted the elderly man multiple times before twisting his neck, and fleeing to Mexico. There he killed an American and was sentenced to 20 years, before being extradited back to New York state in 2007.

Before killing Rickerson, he had served time for rape and for stabbing a nurse, in separate cases. It is also Matt's second jail break. In 1986, he spent four days on the run from Erie County Jail, where he was serving time for assault.

Sweat was serving a life sentence without parole for murdering a sheriff's deputy in New York state in 2002 when he was 22 years old.

He and two accomplices were sharing out a cache of stolen weapons, when the deputy approached them. Sweat and an accomplice shot him several times and drove over him with a car. As a teenager, Sweat was also charged with attempted second-degree burglary and burglary in two separate incidents.

The pair, who were reported to enjoy special privileges in jail, escaped before dawn Saturday in a conspiracy likened to Hollywood movies such as The Shawshank Redemption or Escape from Alcatraz.

They cut through the walls of their cells with power tools, then crawled to freedom through an underground pipe system, coming up through a manhole and leaving behind a note saying "Have a Nice Day" next to a toothy grin.

Two Dannemora residents claim they confronted the felons shortly at around 12:30 am Saturday. One had a buzz cut and wore a white T-shirt with a black guitar case slung over his shoulder, one of the witnesses told ABC News.

"I go look at him and I ask him: 'What the hell are you doing in my yard? Get the hell out of here.' And he was like: 'Sorry, I didn't know where I was. I'm on the wrong street'," the witness said. "Lucky to be alive, man," said his female friend when asked how she felt.

On Monday, New York Governor Andrew Cuomo described the pair as "truly dangerous, desperate men" whose escape "could have been a movie script." Cuomo said he believed they had help, "primarily from the inside" and US media have reported that a female prison worker has been questioned, although not charged in connection with the investigation.

There is a $100,000 reward for information leading to their arrest.