Attorney General Eric Holder has come under fire from House Republicans for not revealing information about Operation Fast and Furious. (Radio News Service/Creative Commons)

Federal authorities charged five men and offered up to $1 million for information leading to the arrest of the four still at large in connection to the botched gun-smuggling investigation known as Operation Fast and Furious, CNN reported.

Launched in 2009, Operation Fast and Furious targeted gun-trafficking kingpins, but federal agents lost track of about 1,400 of the more than 2,000 weapons, according to the Associated Press. Some of the guns purchased illegally later turned up at crime scenes in Mexico and the U.S.

More from the AP:

"The FBI says it is seeking information related to Jesus Rosario Favela-Astorga, 31, Ivan Soto-Barraza, 34, Heraclio Osorio-Arellanes, 34, and Lionel Portillo-Meza.

Portillo-Meza's age and birthplace were unavailable. The other three fugitives were born in Mexico, but their hometowns were not available.

Authorities had previously released the identity of the fifth suspect, Manuel Osorio-Arellanes, of El Fuerte in the Mexican state of Sinaloa. He was shot during the gunfight, and has been in custody since the night of the shooting. He has pleaded not guilty in the case, telling investigators that he raised his weapon toward the agents during the shootout but didn't fire, the FBI said in records."

A sixth defendant, Rito Osorio-Arellanes, faces lesser charges in the case.

The announcement comes after U.S. House Republicans led a vote to hold Attorney General Eric Holder in contempt of Congress, criticizing Holder of withholding information related to the program.

"Agent Terry served his country honorably and made the ultimate sacrifice in trying to protect it from harm, and we will stop at nothing to bring those responsible for his murder to justice," Holder said.

Rep. Darrell Issa of California, who is the chairman of the House Oversight and Government Reform Committee, praised the department for its announcement, but called the timing of the reward money “another example of using politics over good policy,” according to Fox News.

"I applaud what they're doing, but I condemn the timing. It's very clear that the timing has everything to do with the House of Representatives holding Eric Holder in contempt," Issa said.

Patrick McGroder, an attorney for the Terry family, said in a statement that Monday’s disclosures show that the prosecution is making progress, but added that Holder’s office should release the documents requested by members of Congress.

"Agent Terry died as a hero protecting this country; he and his family rightly deserve a full and thorough explanation of how Operation Fast and Furious came to be," McGroder said in the statement from the family.

For more of Neon Tommy's coverage on Operation Fast and Furious, click here.

Reach Executive Producer Danny Lee here; follow him here.