Police dogs have 'detected evidence' of US fugitives
Police bloodhounds have found where David Sweat and Richard Matt may have spent the night after they escaped from prison six days ago.
Food wrappers and other evidence were discovered in the woods nearby the prison according to US media reports.
Police have been receiving hundreds of tips from the public, and a sighting has been reported in Philadelphia.
"Follow every lead you have" Governor Andrew Cuomo told police as the search extended into Vermont.
"Follow them as if it's the lead that's going to break the case. I am confident we are going to find them, the only question is when."
The manhunt in northern New York and surrounding areas has also reached into campsites and boat slips in neighbouring Vermont.
Uninhabited vacation homes are being searched in the popular tourist region.
Homeowners are being asked to leave their outdoor lights on overnight to aid police in the search.
Mr Shumlin and Mr Cuomo held a joint press conference outside the maximum security prison from where the men escaped, Clinton Correctional Facility.
"New York was going to be hot. Vermont would be cooler, in terms of law enforcement," Mr Shumlin said, referring to the unspecified information about the men's whereabouts.
Rainstorms have complicated efforts by masking scents detectable by search dogs and forcing officers to wade through swamps.
Officials at the Saranac Central School District, less than a mile from the prison, closed schools on Thursday "in order to assist law enforcement personnel with their search efforts, and due to the closure of a number of roads".
Police have interviewed a cab driver in Philadelphia, who told authorities to say he may have given a ride to the men early on Thursday morning. But police later ruled that out as a lead.
- 5 June: David Sweat and Richard Matt escape from Clinton Correctional Facility in Dannemora
- 6-7 June: Possible sighting of pair in Dannemora
- 9 June: Search focuses on Willsboro area after another possible sighting
- 10 June: Police close off Route 374 between Dannemora and Cadyville and search expands to neighbouring Vermont
- 11 June: Police dogs find food wrapper and footprint at suspected camp site near Dannemora
Police confirmed on Wednesday that they had interviewed "one woman in particular" who may have befriended the inmates and had a role in their escape, but would not go into detail.
That woman "may had had some role in assisting them", said New York state police superintendent Joseph D'Amico.
Matt was given a jail term of 25 years to life for beating a man to death in 1997.
Sweat was serving a life sentence without parole for the murder of Broome County Sheriff's Deputy, Kevin Tarsia.