Sunni Muslim-ruled Bahrain accused Shiite Iran on Tuesday of having formed a "terrorist cell" busted at the weekend, saying its aim was to foster violence in the Gulf kingdom.
The announcement was the latest in a series of claims that Iran was backing activists demanding a greater say for the Shiite majority in Bahrain's politics and likely to exacerbate tensions between the two neighbours.
General Tareq al-Hassan, who heads the general security agency, told a news conference members of the cell were to have "brought in arms and explosives and to launch operations at a moment decided by their command in Iran."
He said they had been recruited by two Iran-based Bahrainis and were commanded by a member of Tehran's elite Revolutionary Guards named Abu Nasser.
He said they had undergone training by the Guards in Iran and also by the Lebanese Shiite movement Hezbollah in Iraq, as well as received financial support.
They were tasked with collecting intelligence and taking photographs of sensitive sites and military installations, as well as preparing depots and stocking arms until receiving orders to act.
On Saturday, Interior Minister Sheikh Rashid bin Abdullah al-Khalifa said a "terrorist cell" linked to Iran, Iraq and Lebanon had been dismantled, slamming what he called "escalation" as the Shiite opposition intensifies its protests.
Security services "have, with the help of a brotherly country, arrested the members of a terrorist cell made up of eight Bahraini elements," he was quoted as saying.
The eight "moved between Iran, Iraq and Lebanon and received training in using arms and explosives as well as financial aid," he said.
Bahrain has seen two years of political upheaval linked to opposition demands for a real constitutional monarchy, with the unrest claiming at least 80 lives, according to international rights groups.
The latest unrest comes against the background of a fresh round of a national dialogue between opposition groups and the government.