The authorities in Azerbaijan have arrested 22 people on suspicion of spying for Iran, accusing them of links to the Iranian Revolutionary Guards.
The undated arrests were confirmed in a brief statement by the Azerbaijani national security ministry.
Azerbaijani TV reported last month that a plot to attack the Israeli embassy and a Jewish centre had been foiled.
At the time, Iran was also suspected of attacking Israeli targets in Thailand, India and Georgia.
It was not immediately clear on Wednesday if these were new arrests, or official confirmation of those made in February.
However, according to Contact, a non-government Azerbaijani news website supported by the US National Endowment for Democracy, the arrests took place between late January and 20 February.
Contact said the detainees were being charged with treason and illegal possession of weapons.
It added that they were "not the first group of individuals... arrested recently in Azerbaijan on charges of working for the Iranian secret services".
"Firearms, cartridges, explosives and espionage equipment were found during the arrest," the Azerbaijani national security ministry said.
The 22 detainees are said to have received orders from the Revolutionary Guards to "commit terrorist acts against the US, Israeli and other Western states' embassies and the embassies' employees".
Recruited as far back as 1999, they were allegedly trained in the use of weapons and spy techniques at military camps in Iran.
Iran and Israel appear to be engaged in a covert war of threats, bomb attacks and assassination plots in the Caucasus, the BBC's Damien McGuinness reported recently.
Recent tensions suggest that Iranian spies and agents of Israel's secret service Mossad are active in the southern Caucasus, made up of Georgia, Azerbaijan and Armenia, our Tbilisi correspondent adds.
Iran says Azerbaijanis have been helping Israeli assassinations in Iran.
The development of Azerbajiani oil and gas in the Caspian Sea, with major export pipelines pumping energy to Western markets, heightens the region's strategic importance.