Authorities in Maine launched a dragnet Wednesday after a man shot and killed a sheriff’s deputy, stole his cruiser and then robbed a convenience store, officials said.

Somerset County Sheriff Dale Lancaster said Corporal Eugene Cole was killed around 1:45 a.m. on U.S. Route 2 in Norridgewock, located about 30 miles north of the state capital of Augusta. Cole was one of two cops shot dead nationwide, with a Dallas police officer succumbing to his wounds Wednesday morning after being injured the day before.

"He was one of the finest deputies that you would want to meet," Lancaster said of Cole at a news conference.

Authorities said the suspect, 29-year-old John Williams, stole Cole's police cruiser after the shooting and drove it to a Cumberland Farms store, a 24-hour gas and convenience store, and robbed it. Lancaster did not not disclose any details about what happened before the deputy was shot.

After fleeing the store, Williams abandoned the vehicle, which was found around 5 a.m., officials said. It is not known if Williams is in another vehicle or on foot.

"Many times we're able to say that there is not an ongoing threat, but that's not the case today," State Police Lt. Col. John Cote said at a news conference. "There certainly is an ongoing public threat. He's considered armed and dangerous."

Lancaster said during an evening news conference that "this still remains a very active investigation" and authorities had been following up on leads over the course of the day.

"As of this briefing, do not approach Williams," Lancaster said. "He remains armed and extremely dangerous."

Williams is described as being 5-foot-6, 120 pounds and having blue eyes and brown hair in a ponytail, Lancaster said.

Williams was previously arrested in Massachusetts on March 22 on firearms violations, according to a police report. Carrie Kimball-Monahan, spokeswoman for the Essex District Attorney's Office, told The Associated Press that Williams posted $5,000 bail and was supposed to return to court Wednesday for a hearing.

The FBI told WGME they are sending assistance to help the Somerset County Sheriff's Office and Maine State Police with the investigation.

Cole was a member of the sheriff's office for 13 years and had a son, according to Lancaster.

"We have lost an outstanding deputy today," he said.

Authorities are now conducting a manhunt in the area, including using helicopters to try to locate Williams.

OFFICERS KILLED IN THE LINE OF DUTY IN 2018

Maine Gov. Paul LePage asked for residents in Somerset County and the surrounding area to "stay safe"

"Our deepest condolences go out to the family of fallen Deputy Sheriff Corporal Eugene Cole," LePage wrote on Twitter. "If you live in Somerset County and the surrounding area, please cooperate with law enforcement and stay safe."

Senator Susan Collins said on Twitter she was "deeply saddened" by the news.

"I am deeply saddened to learn Cpl. Eugene Cole was killed in the line of duty in Norridgewock this morning," Collins said. "Cpl. Cole served the citizens of Somerset County for 13 years with honor & distinction, & Maine will be eternally grateful for his brave actions to protect his community."

Residents of the town of about 3,500 people were urged to be vigilant, as there are heavy woods in the area. Authorities had guns drawn outside of a home in Madison where the suspect lives, located about 8 miles from the scene of the shooting.

"We're a little on edge. It's unnerving knowing there's a guy running around out there," Tasha Raymond, who was home with her two children, told The Associated Press.

The last time a Maine officer was shot and killed in the line of duty was 29 years ago on March 31, 1989, according to WGME. Maine State Police Detective Giles Landry was gunned down in his police cruiser outside a mobile home in Leeds while investigating a child abuse case.

Fox News' Shira Bush, Elizabeth Zwirz and The Associated Press contributed to this report.