Squads of law enforcement officers are heading out for a seventh day of searching for two murderers who escaped from a maximum-security prison in northern New York.

Armed officers in body armor started boarding New York state prison system buses soon after dawn Friday in the village of Dannemora, where David Sweat and Richard Matt used power tools to cut their way out of their neighboring cells last weekend. They remain at large.

The hundreds of state, federal and local officers conducting the search spent Thursday slogging through a swampy patch of woods just east of Dannemora after investigators had received tips that the convicts were in the area. Tracking dogs had picked up the scent in the morning.

State Route 374, the main road leading into Dannemora, remains closed for a second day, as does the local school district.

The rugged northern New York terrain being searched for two escaped murderers presents major challenges to anyone who ventures into the Adirondack woods.

Experts say if escapees David Sweat and Richard Matt are in the wooded, swampy area just east of Clinton Correctional Facility in Dannemora, they’re enduring two of the region’s warm-weather nuisances: swarms of biting insects.

Curt Stager, a biology professor at Paul Smith’s College in the Adirondacks, tells the Press-Republican of Plattsburgh that black flies come out during the day while mosquitoes are just as prevalent at night.

The hundreds of law enforcement officers attempting to catch the escapees are encountering the same conditions as they slog through streams and swamps in the search area, located near the Adirondack Park’s northeastern boundary about 20 miles south of the Canadian border.

(AP)