A US federal grand jury Tuesday indicted a company based near Seoul and three South Korean men with illegally exporting military technology to South Korea.

Incheon-based EO System Company Ltd. was charged, along with Lee Seok-Hwan, Kim Tae-Young and Lee Won-Seung, with five counts of helping to export infrared telescopes and detectors which had been placed on a US Munitions List.

According to the indictment by the jury in Cleveland, Ohio, the men were accused of knowingly and willfully exporting, causing to be exported and aiding and abetting the export of such defense articles without the right permits.

Around November 2005 five infrared telescopes, also known as infrared focal plane array detectors and infrared camera engines, were exported from the US to South Korea.

"These defendants are charged with violating important regulations designed to protect national security," US Attorney Steven Dettelbach said in a statement.

FBI Special Agent in Charge Stephen Anthony said "the FBI and Department of Justice are committed to the protection of US defense technology, particularly that which is governed by the International Traffic in Arms Regulations."