Missile technology, fighter jet parts, night vision goggles and other U.S. wartime equipment increasingly are being illegally smuggled to potential adversaries, such as China and Iran, the federal government said.

Last week, two men were arrested for allegedly trying to sell parts over the Internet for F-4 and F-14 fighter jets — which are only flown by Iran. The week before, two engineers were indicted on charges of stealing computer chip designs intended for the Chinese military.

Officials acknowledged Thursday that some smuggled equipment might be used for peaceful purposes, such as spark gaps that are used in medical machines to break up kidney stones but also can trigger nuclear detonations. Government lawyers and investigators described a growing number of unauthorized exports that could be dangerous if they end up in the hands of terrorists or hostile nations.

"The concept of terrorists, criminals or rogue nations obtaining weapons and other restricted technology is chilling," said Homeland Security Assistant Secretary Julie Myers, who oversees illegal export investigations as head of the U.S. Immigration and Customs Enforcement.

Assistant Attorney General Ken Wainstein called new government efforts to crack down on illegal exports the Justice Department's top counterintelligence priority.

A Defense Department report noted a 43 percent increase in 2005 in what it described as suspicious foreign contacts with U.S-based defense companies. Another report last year by U.S. intelligence officials found that a record 108 nations were trying to buy or otherwise obtain U.S. technology that is restricted for sale. It did not list which nations or specify whether some of them were U.S. allies.

Night vision goggles, body armor and equipment used in improvised explosive devices, or IEDs, have been in particular demand since the 2001 terror attacks that prompted the U.S.-led invasions of Afghanistan and Iraq, officials said. But some prosecutors have been reluctant to pursue the smugglers because illegal export cases can be very complicated and time-consuming to chase.

"These are incredibly complicated cases," Wainstein said, adding that training and assistance will be given to prosecutors and investigators working on a new task force under the departments of State, Justice, Homeland Security, Defense, Commerce and the FBI. The task force largely will focus on U.S.-based exporters who sell or ship equipment overseas without proper authorization.

Other recent smuggling cases of concern to national security officials include:

—An Indonesian man was indicted Thursday on charges of conspiring to export rifle scopes to Indonesia.

—SparesGlobal, Inc., was put on probation for a year and fined $40,000 (euro28,170) last week for lying about exporting equipment used in nuclear reactors and ballistic missiles in 2003 that ended up in Pakistan.

—A man pleaded guilty in August to trying to smuggle 100,000 Uzi submachine guns and night vision goggles to Iranian government officials.

—Two men pleaded guilty on the same day, Aug. 1, to exporting military-use technology to China, including, in one case, computer code to help train fighter pilots.