Bahrain Mirror (AFP): A leading Iranian general has warned Bahrain it is fanning armed rebellion and "will pay the price" after a crackdown on its Shiite majority saw the community's spiritual leader stripped of his nationality.

The warning from General Qassem Suleimani, head of the elite Revolutionary Guards' overseas operations arm, the Quds Force, came after Washington too strongly criticised the move by its Gulf Arab ally.

"Surely they know that the aggression against Ayatollah Sheikh Isa Qassim is a red line... that will leave no option for the people but to resort to armed resistance," Suleimani told state media late on Monday.

Bahrain's rulers "will pay the price and it will have no result but the destruction of this bloodthirsty regime," he added.

It was a rare public pronouncement from Suleimani. As Iran has stepped up its military involvement in neighbouring Iraq and in Syria, he has adopted an increasingly high profile but he still rarely speaks out on policy issues.

Iran has long championed the rights of Bahrain's Shiite majority against the kingdom's autocratic Sunni ruling family.

But it denies Manama's accusations that it has incited violence in the kingdom.

The Bahraini interior ministry alluded to the accusations in its statement announcing the decision against the Shiite spiritual leader on Monday.

Sheikh Qassim abused his position to "serve foreign interests and promote... sectarianism and violence," it said.

Bahrain has been shaken by unrest since security forces crushed Shiite-led protests demanding a constitutional monarchy and an elected prime minister in 2011.

Despite repeated calls from their Western allies, Bahrain's rulers have made no concessions to the Shiite opposition but have instead launched an intensifying crackdown.

In 2015, authorities stripped 208 Bahrainis of their citizenship, according to the US-based Human Rights Watch. It says at least five people whose nationality had been revoked were deported between February and March alone.

The decision against Qassim follows the suspension of Bahrain's main Shiite opposition group, Al-Wefaq, whose political chief Sheikh Ali Salman is serving a nine-year jail term on charges of inciting violence.

Al-Wefaq was the largest faction in parliament before its members quit in protest at the 2011 crackdown.

Iran's foreign ministry criticised the "extrajudicial" measures by Bahrain that "dash hopes of reform through dialogue and peaceful overtures".

It urged Bahrain's rulers to "avoid destroying all the bridges of contact with the people and moderate leaders" by "accepting the realities of the country and holding serious national dialogue".

Washington too strongly criticised the decision by Bahrain, a close ally which hosts the US Fifth Fleet.

"We are alarmed by the government of Bahrain's decision to revoke the citizenship of prominent Shia cleric Sheikh Isa Qassim," State Department spokesman John Kirby said.

"We remain deeply troubled by the government of Bahrain's practice of withdrawing the nationality of its citizens arbitrarily."

The protests in Bahrain and Shiite-majority areas of neighbouring Saudi Arabia have exacerbated tensions between Shiite Iran and Sunni-ruled Gulf Arab states, that were already running high over the conflicts in Syria and Yemen.

In January, Saudi authorities executed Shiite cleric Sheikh Nimr al-Nimr, who was a prominent figure in 2011 demonstrations in the east of the kingdom that followed the protests in Bahrain.

His execution sparked protests in Tehran and Iran's second city Mashhad that saw Saudi diplomatic missions torched and diplomatic relations cut.