The seven operated their network since at least 2017 on behalf of Serniya Engineering and Sertal LLC, two Russian companies already on US sanctions blacklists.

The two companies operated "under the direction of Russian intelligence services" to obtain advanced electronics and testing equipment for Russia's military, science and industrial sectors, according to a Justice Department Statement.

Some of the equipment was useful in quantum computing, hypersonic and nuclear weapons development and other military and space uses, it said.

The group masked their procurement, using the two New York-based Americans to acquire the goods and disguising payments and shipping through shell companies and multiple bank accounts.

The goods were shipped through Estonia, Finland, Germany and Hong Kong, according to the indictment filed in federal court in Brooklyn.

The activity continued after the two companies and one of the defendants were placed under sanctions in March following Russia's invasion of Ukraine.

In October one of the Russian defendants, Vadim Konoshchenok, whom the indictment called a "suspected FSB officer," was stopped in Estonia as he sought to cross the border into Russia carrying 35 types of semiconductors and thousands of US-made 6.5mm bullets used in sniper rifles.

In November he was stopped again carrying about 20 cases of US-made tactical bullets and sniper rounds, according to the indictment.

The seven face 16 counts of fraud, conspiracy, smuggling, money laundering and sanctions violations.

One of the Russians was arrested Tuesday and the second turned himself in to authorities.

Konoshchenok was arrested on December 6 by Estonian authorities on a US request and is facing extradition to the United States.

The other four are at large, the Justice Department said.