(CNN) The U.S. Marshals Service issued federal arrest warrants Sunday for two convicted killers who escaped from a maximum security prison in upstate New York over the weekend.

The warrants charge Richard Matt and David Sweat with unlawful flight to avoid prosecution, according to William O'Toole, a U.S. Marshals Service spokesman. The warrants clear the way for the federal government to involve its considerable resources in the manhunt.

"Every resource available to us will be used in bringing these two men to justice," O'Toole said.

Officials look at the manhole through which the inmates crawled to freedom.

Officials look at the manhole through which the inmates crawled to freedom.

Gov. Cuomo examines a pipe the inmates cut through. Authorities don't know how the prisoners got the power tools.

Gov. Cuomo examines a pipe the inmates cut through. Authorities don't know how the prisoners got the power tools.

The inmates used power tools to drill through steel pipes as they made their escape.

The inmates used power tools to drill through steel pipes as they made their escape.

Cuomo examines the escape route of the prisoners. "It was elaborate; it was sophisticated," he said.

Cuomo examines the escape route of the prisoners. "It was elaborate; it was sophisticated," he said.

Gov. Cuomo studies the maze of pipes the prisoners navigated during their escape.

Gov. Cuomo studies the maze of pipes the prisoners navigated during their escape.

Looking from the catwalk, this is the hole the inmates cut into the wall. The pair followed the catwalk toward a series of tunnels.

Looking from the catwalk, this is the hole the inmates cut into the wall. The pair followed the catwalk toward a series of tunnels.

The hole the inmates cut into a cell wall to escape. The men had side-by-side cells and apparently had obtained power tools to cut through the steel wall, authorities said.

The hole the inmates cut into a cell wall to escape. The men had side-by-side cells and apparently had obtained power tools to cut through the steel wall, authorities said.

Gov. Andrew Cuomo, shown during a tour of the prison, said of the escapees: "These are dangerous people. They are nothing to be trifled with."

Gov. Andrew Cuomo, shown during a tour of the prison, said of the escapees: "These are dangerous people. They are nothing to be trifled with."

Richard Matt, left, and David Sweat were discovered missing on Saturday, June 6, at the 5:30 a.m. "standing count" of inmates at the Clinton Correctional Facility in Dannemora, New York.

Richard Matt, left, and David Sweat were discovered missing on Saturday, June 6, at the 5:30 a.m. "standing count" of inmates at the Clinton Correctional Facility in Dannemora, New York.

Also Sunday, New York Gov. Andrew Cuomo announced a $100,000 reward for information leading to the pair's capture.

"We're leaving no stone unturned," Maj. Charles Guess of the New York State Police said Sunday. "All available assets are being brought to bear."

Matt, 48, and Sweat, 35, were discovered missing from their cells Saturday morning during a "standing count" of inmates at the Clinton Correctional Facility in Dannemora, New York, state police said.

The pair used power tools and decoys designed to look like their sleeping selves in the sophisticated plot, they said.

According to authorities, the inmates -- who occupied side-by-side cells -- cut through a steel wall and followed a series of tunnels until they emerged from a manhole outside the prison walls.

'They could be literally anywhere'

Guess said authorities do not know if the pair are still together, had help on the outside, or if they have access to a vehicle.

Although they've received more than 150 leads, Guess said Sunday that "they could be literally anywhere."

In addition to the federal marshals service, the FBI is also among the some 250 law enforcement officials involved in the manhunt, according to Guess.

With the facility's proximity to Canada, only 80 miles south of Montreal, and with one of the inmates having ties to Mexico, he said authorities on both international borders have been alerted.

Matt, who has "Mexico Forever" on his back, is well known to Mexican authorities. In 2007, he was extradited from Mexico back to New York on a decade-old murder charge, documents from the Mexican Attorney General's office and New York State Police show.

An elaborate escape

Matt and Sweat apparently were last seen at 10:30 p.m. Friday during a standing count, authorities said.

Head counts are performed every two hours throughout the night when guards visually check to see whether inmates are in their bunks, Clinton Correctional Facility Supervisor Steven Racette said.

The escapees tricked the guards by arranging things in the bunks to look "like people were sleeping ... with these sweatshirt hoodies on," the governor said.

Once they were out of their cells, they then followed a catwalk "down an elaborate maze of pipes into tunnels and exited a series of tunnels at the manhole cover," he said.

They evaded detection for some seven hours, until the inmate count 5:30 a.m. Saturday.

Exactly how they got the necessary tools remains a mystery, but Cuomo -- who toured the escape route Sunday -- said it was possible the tools came from workers performing regular maintenance on the 1845 facility.

Photo: In the cell of one of escaped inmates, looking at the hole cut in the wall as part of escape pic.twitter.com/tGAtt8xHyb — Andrew Cuomo (@NYGovCuomo) June 6, 2015

"It was elaborate, it was sophisticated," he said of the plot. "It involved drilling through steel walls, steel pipes."

Guess said the company who employs the maintenance workers was cooperating with the investigation.

"These are dangerous people"

The facility, in the sparsely populated northeast corner of New York, is the state's largest prison with a population of 2,689 inmates, the corrections department said. Clinton Correctional Facility's nickname is "Little Siberia," because of its remote location, in a region where wintry weather can persist for more than half the year.

"These are dangerous people," Cuomo said. "They are nothing to be trifled with."

Richard Matt is white, 6 feet tall and weighs 210 pounds. He has black hair, hazel eyes and several tattoos in addition to the "Mexico Forever" on his back, including a heart on his chest and left shoulder, and a Marine Corps insignia on his right shoulder. He was convicted on three counts of murder, three counts of kidnapping and two counts of robbery after he kidnapped a man and beat him to death in December 1997, state police said. He was sentenced to 25 years to life in prison.

David Sweat is white, 5 feet, 11 inches tall and weighs 165 pounds. He has brown hair, green eyes and tattoos on his left bicep and his right fingers. He was serving life without parole after his conviction of first-degree murder in the death of a Broome County, New York, sheriff's deputy in July 2002, state police said.

Authorities ask anyone who sees them to call New York State Police or 911.