US and Austrian authorities have arrested two Iranian men on charges of attempting to illegally export thousands of sophisticated American night-vision systems for Iran's military, US officials have said. The alleged transactions were eventually expected to involved about 3000 of the advanced helmet-mounted Generation III systems, which can amplify even faint starlight so that soldiers can see to fight in the dark. "Sophisticated night vision systems allow US troops to own the night, giving them a key advantage over their opponents during night-time combat. In the wrong hands, these night vision systems pose a threat to our troops around the world," said Michael J Garcia, chief of US Immigration and Customs Enforcement (ICE). The two suspects, Mahmoud Seif and Shahrzad Mir Gholikhan, were arrested earlier this week on export violation charges in Vienna, Austria, by US and Austrian authorities shortly after they arrived to pick up their first batch of night-vision equipment. The investigation dates to August 2002 and involves ICE, the Defence Criminal Investigative Service and Austrian security personnel.