Bahrain’s introduced martial law in an effort to end weeks of anti-government protests.
It comes a day after Saudi troops moved into the Sunni-ruled island to quell the unrest.
The kingdom also declared a three month state of emergency which will hand considerable powers to Bahrain’s security forces.
State television meanwhile said that a Bahraini policeman was killed in riots, refuting some reports that a Saudi soldier had died.
In a sign of continued disturbances in the tiny kingdom, an opposition politician said a Bahraini man was killed and several wounded in clashes with police in the Shi’ite area of Sitra.
Iran, Britain and the United States rarely see eye to eye but they all say they are increasingly concerned over the situation.
Iran’s foreign ministry spokesman also attacked the presence of foreign forces in Bahrain: “We generally don’t approve of military interference in Gulf region countries and in dealing with people’s demands. Aggravation and violence will not resolve anything.”
In a sign that neither side is ready to budge, thousands marched on the Saudi embassy while thousands more remain camped out at Manama’s Pearl Square in protest against the government.