The ministry in a statement listed the dozens stripped of their citizenship, which it said included dependents, adding they "were found to have supported hostile Iranian acts, including colluding with foreign entities".

The Bahrain Institute for Rights and Democracy (BIRD) described the decision as "the first mass revocation of citizenship since 2019".

The rights group said it was unclear whether those affected had been arrested, whether they were inside or outside the country, or whether they held other nationalities.

Iran launched waves of missile and drones against Gulf states including Bahrain in response to US and Israeli strikes on the Islamic republic that began on February 28.

Tehran accused them of allowing the US to use their territory as launchpads for strikes.

The Iranian attacks, which targeted US military bases in the region as well as critical infrastructure in the Gulf states, have halted since a fragile April 8 ceasefire announced by Washington and Tehran.

The move by Bahrain comes as Gulf countries are on high alert over Iranian infiltration, with Qatar, Kuwait and the UAE cracking down on what they call Iran-related networks.

But the effect of the war with Iran, Bahrain's much larger Shia neighbour, has had a pronounced impact on the island kingdom, ruled by a Sunni Muslim dynasty, home to a large Shia population that has long complained of marginalisation.

Human Rights Watch (HRW) last month expressed alarm after the arrests of "dozens of people" since the start of the Middle East war.

Some of those detained were accused of treason, while others were arrested for protesting.