DANNEMORA, N.Y. — State police expanded the search Wednesday for two escaped murderers beyond a 16-square-mile area of woods, fields and swamps where the manhunt has been most intense.

Clinton County Sheriff David Favro said Tuesday that rain in recent days has been washing away any scent dogs might find and interfering with thermal imaging devices used to detect body heat.

No vehicles were reported stolen in the area, which leads searchers to believe convicts David Sweat and Richard Matt were still near the prison they escaped from.

Search dogs earlier caught the scent of the men, and authorities found evidence indicating they may have spent time there.

More than 800 law enforcement officers who are combing the rural area now have shifted their focus eastward along Route 374 leading from the village of Dannemora, home of the Clinton Correctional Facility, in far northern New York.