(CNN) Two Chinese intelligence officers have been charged by the United States Justice Department with trying to steal the details for a type of jet engine technology from US-based companies.

Zha Rong and Chai Meng, intelligence officers with the Jiangsu provincial branch of the Ministry of State Security (MSS) in China, are accused of attempting to hack and infiltrate private companies over the course of five years in an attempt to steal the technology.

"This action is yet another example of criminal efforts by the MSS to facilitate the theft of private data for China's commercial gain," US Attorney Adam Braverman said in a statement.

"The concerted effort to steal, rather than simply purchase, commercially available products should offend every company that invests talent, energy, and shareholder money into the development of products."

The US Department of Justice statement does not explicitly state where Zha Rong and Chai Meng are presently located. The United States does not have an extradition treaty with China -- and if the men are in China, the Chinese government would be unlikely to give them up.

On Wednesday, China's Foreign Ministry spokesman Lu Kang dismissed the charges as "sheer fiction and completely fabricated."

The charges come at a time when pressure is building on Beijing to address US concerns over the widespread alleged theft of intellectual property by Chinese agents to fuel the country's economic rise.

The new charges mark the third time since September that charges have been brought against Chinese intelligence officers for trying to steal US intellectual property.

On October 11, the Department of Justice charged Chinese intelligence officer Yanjun Xu with attempting to commit economic espionage, including working to get aviation employees to reveal their trade secrets. A Chinese Foreign Ministry spokesman dismissed the allegation as "pure fabrication" at the time.

In an indictment released by the Justice Department Tuesday, the US Justice Department alleged Zha and Chai from January 2010 began to work with a team of hackers to steal the technology for the engine which was being developed jointly by a French and a US-based company.

"At the time of the intrusions, a Chinese state-owned aerospace company was working to develop a comparable engine for use in commercial aircraft manufactured in China and elsewhere," the statement said.

Attempts to infiltrate the company weren't limited to hacking, according to the US statement. Two Chinese nationals working for the company, Tian Xi and Gu Gen were allegedly co-opted by Chinese intelligence and given malware to install in their employer's computer system.

"The threat posed by Chinese government-sponsored hacking activity is real and relentless," John Brown, FBI Special Agent in Charge of the San Diego Field Office, said in a statement.