Those arrested are accused of exporting arms and armament systems
Two Iranians and five Italians have been arrested by Italian police on suspicion of trafficking arms to Iran, anti-terror police say.
Two more Iranian suspects are currently in Iran, Italian officials say.
Italy's anti-terrorist prosecutor Armando Spataro said the two Iranians arrested in Italy worked for the Iranian government.
He said they were accused of exporting arms and armament systems, and breaking a UN arms embargo on Iran.
"It is an investigation of considerable importance because it concerns the entire international community," said Mr Spataro of the nine-month operation, codenamed Sniper.
It was conducted along with Swiss police as one of the suspects lived in Bern, he added.
An earlier statement said those sought were suspected members of the Iranian secret service.
Italy is Iran's biggest trading partner in the European Union.
But it has been among the countries leading calls for tougher sanctions against Iran over its nuclear programme.
The West accuses Iran of seeking to build nuclear weapons. Iran denies this, saying its only aim is to generate nuclear energy.