The manhunt for two convicted murderers who escaped from a maximum-security prison in New York state was extended to neighbouring Vermont on Wednesday, the governors of the two states said as the police search entered its fifth day, according to dpa. David Sweat, 34, and Richard Matt, 48, were discovered missing from their cells Saturday morning at the Clinton Correctional Facility in northern New York state about 500 kilometres north of New York City. Despite intensive efforts by local and federal police, including house-to-house sweeps, the prisoners have remained on the loose. Authorities in Vermont state were notified Wednesday that the fugitives might have crossed the state border. "We have information that suggests that they thought that New York was going to be hot [and] Vermont would be cooler in terms of law enforcement and that a camp in Vermont might be a better place to be than New York," said Vermont Governor Peter Shumlin at the joint press conference in front of the prison. It was said by New York officials to be the first escape from the maximum-security portion of the prison which opened in 1865. The greater prison, which opened in 1845, is known as "Little Siberia" for the cold weather in upstate New York. New York Governor Andrew Cuomo said that capturing the men was the highest priority and urged residents in both states to be vigilant and careful. "We need to find these escapees," Cuomo said. "They are dangerous men, they are killers, they are murderers, there's no reason to believe they wouldn't do it again." The inmates used power tools to drill through a steel wall, pipes and stone to escape underground and emerge through a manhole on a street several metres from the prison wall. Before slipping out they shaped dummies out of clothing and put them into their beds to dupe guards. Authorities are offering a 100,000-dollar reward for information leading to their capture. Sweat was sentenced to life for killing a sheriff's deputy, and Matt was sent to jail for 25 years-to-life for three counts of murder, three counts of kidnapping and two counts of robbery.