Bahrain on Monday banned opposition groups from having contacts with Hezbollah, as the Sunni-ruled kingdom moves to limit the Lebanese Shiite movement's suspected influence on its restive Shiite majority.
Last month the Gulf state listed Hezbollah as a "terrorist organisation" -- in line with the United States -- following a recommendation by the parliament that is boycotted by the opposition.
Its latest decision appears aimed at stifling Shiite political associations which led anti-regime protests that erupted in February 2011 before security forces crushed them a month later.
"Political associations are prohibited from having any form of contact with the Hezbollah organisation," Justice Minister Sheikh Khaled bin Ali al-Khalifa said in a ministerial decree.
A second clause in the decree stated the Iran- and Syria-backed group was a "terrorist organisation".
During the 2011 protests, Hezbollah repeatedly slammed Bahrain for cracking down on Shiite demonstrators, drawing angry rebuttals from Manama which accused the Lebanese group of meddling in its internal affairs.
Foreign Minister Sheikh Khaled bin Ahmed al-Khalifa on Sunday branded Hezbollah chief Hassan Nasrallah as a "terrorist", in remarks a day after Nasrallah vowed to keep up the fight alongside regime forces in Syria to defeat rebels.
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"Terrorist Nasrallah has declared war on his nation," Sheikh Khaled wrote on his Twitter account.
"Stopping him and rescuing Lebanon from his grip is a national and religious duty for all of us," he said, as Hezbollah's involvement in Syria's armed conflict deepened.
Nasrallah is a popular figure among the Shiites of Bahrain.
But the Shiite-led opposition clamouring for reforms has repeatedly insisted its political agenda is purely Bahraini, denying any links to Iran or other Shiite forces.
Bahrain and other Gulf states repeatedly accuse Shiite-dominated Iran of meddling in their affairs, a charge that the Islamic republic categorically denies.
Bahrain's security forces were in March 2011 boosted by Gulf troops, led by Sunni-ruled Saudi Arabia, to quell the protests that appeared to take their cue from Arab Spring uprisings.
Despite the crackdown, Shiites continue to demonstrate in their villages, frequently clashing with police.
A total of 80 people have been killed since the protests erupted, according to the International Federation for Human Rights.