EATONTON, Ga. -- A manhunt is under way for two inmates accused of killing two guards on a Georgia prison bus Tuesday morning.

A reward of $60,000 is being offered for information leading to the arrests of the fugitives -- 43-year-old Donnie Russell Rowe and 24-year-old Ricky Dubose. Georgia Bureau of Investigation spokeswoman Nelly Miles says the amount is likely to increase.

"My biggest worry is they're going to kill somebody else," Putnam County Sheriff Howard Sills said.

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Georgia Gov. Nathan Deal said he's committing to using every state resource necessary to capture the men.

Rowe and Dubose overpowered and disarmed two guards around 6:45 a.m. as 33 inmates were being driven between prisons, Sills told reporters. One of the two inmates then shot and killed both guards, Sills said.

"We are still desperately looking for these two individuals. They are armed with 9 mm pistols that were taken from these correctional officers. They are dangerous beyond description. If anyone sees them or comes into contact, they need to call 911 immediately," the sheriff said.

Escaped prisoners Donnie Russell Rowe (left) and Ricky Dubose (right) were two of 33 inmates being transported in a bus Tuesday morning when they overpowered two corrections officers on board, stealing their firearms and carjacking a green Honda Civic. Elbert County Sheriff's Office

The FBI said the fugitives were last seen getting into a "grass green," four-door 2004 Honda Civic with the Georgia license plate number RBJ-6601, and driving west on state Highway 16 toward Eatonton, southeast of Atlanta.

CBS affiliate WGCL-TV shared a photo of what is believed to be the stolen vehicle on Twitter.

#RT & #SHARE: Here is the stolen Honda Civic (RBJ-6601), which 2 inmates carjacked earlier this morning in Putnam County on Hwy-16. pic.twitter.com/Es6ktc5Jb5 — CBS46 (@cbs46) June 13, 2017

Sills said the two inmates got a head start by taking and tossing the Honda driver's cellphone and leaving the other 31 prisoners locked inside the bus. He predicted they would break into a house to change out of their prison clothes, and try to switch cars to throw pursuers off their trial.

The Georgia Department of Corrections identified the guards as Christopher Monica and Curtis Billue, both officers at Baldwin State Prison. Monica had been with the department since October 2009 and Billue since July 2007.

Sills was emotional as he described the scene.

"I saw two brutally murdered corrections officers, that's what I saw," he said. "I have their blood on my shoes."

Ricky Dubose and Donnie Russell Rowe are wanted for the murder of two correctional officers in Putnam County, Ga., on Tue., June 13, 2017. A $60,000 reward is being offered for information that leads to both of their arrests. FBI

How the inmates managed to reach and overpower the guards remains under investigation, Sills said.

"They were inside the caged area of the bus," he said. "How they got through the locks and things up to that area I do not know."

Protocol is to have two armed corrections officers on the bus, but the officers don't wear bullet-proof vests during transfers, Corrections Commissioner Greg Dozier said.

"We lost two of our fellow officers, two of our kin. We see our officers as our family," Dozier said.

"The selflessness and courage of these two brave souls will not be forgotten, nor will their sacrifice and service," Gov. Deal said.

Monica was 42 and leaves behind a wife, Dozier said. Billue was 58 and is survived by his father, five sisters, two brothers and two sons, said Jim Green, an attorney speaking for the Billue family.

"Officer Billue's family asks for prayers for all of those who are now placing their own lives at risk to bring these men to justice and asks anyone who has information that may assist in apprehending these perpetrators to please contact law enforcement," Green said in an email.

The guards were moving the inmates to a diagnostics center in Jackson, where their next placement was to be determined, Dozier said, adding that inmates do not know their transfer dates ahead of time.

U.S. Deputy Attorney General Rod Rosenstein said federal resources are being committed to help catch the fugitives. The FBI and U.S. Marshals have joined the investigation, Sills said.

"An attack on any American law enforcement officer is an attack on every American law enforcement officer and the principles we all believe in," Rosenstein told a Senate budget panel in Washington Tuesday morning.

WGCL-TV reports Rowe was convicted on charges of aggravated assault and armed robbery. Dubose was imprisoned after he was found guilty of credit card fraud, armed robbery, theft and aggravated assault.

The Department of Corrections said Rowe has been serving life without parole since 2002, and Dubose began a 20-year sentence in 2015.

Ricky Dubose Georgia Corrections

A photo released by the sheriff's office in Elbert County, the site of his most recent conviction, shows Dubose with prominent tattoos. He appears to have a crown tattooed above his right eyebrow, writing above his left eyebrow and large letters covering the entire front of his neck. Dubose stands 6 feet tall and weighs 150 pounds.

Detectives say Rowe has brown hair and blue eyes. He stands around 6-foot-2 and weighs 150 pounds.

Authorities are urging the public not to approach the men and to call 911 if they spot the pair.

"They need to surrender before we find 'em," Sills said.