Three U.S.-based businessmen have been charged with participating in a long-running conspiracy to illegally export sensitive military-grade electronics to Iran, the Justice Department said Friday.

U.S. authorities allege that the three men and two others worked for an Iranian procurement network that over the past five years evaded U.S. licensing systems designed to stop transfers of sophisticated technology. Among the items shipped to Iran, U.S. authorities said, were sophisticated microelectronics that can be used in surface-to-air and cruise missiles.

Four companies also were charged in the indictment.

“Violations of the International Emergency Economic Powers Act not only can undercut the impact of U.S. sanctions, but can also serve to undermine U.S. foreign policy and adversely affect national security,” Assistant Attorney General John Carlin said in a statement.

The charges come as the U.S. government and five other world powers last week reached a preliminary agreement with Iran to ensure its unable to produce a nuclear weapon in return for lifting economic sanctions.

The indictment unsealed Friday in federal court in Houston comes a month after the Justice Department won what is considered to be the largest criminal fine in a sanctions case. On March 25, Schlumberger Oil Holdings Ltd., a unit of Schlumberger Ltd., agreed to plead guilty to illegally trading with Iran and Sudan, and to pay a penalty of $232.7 million.