Pro-democracy protests in February were followed by a crackdown on dissent by Bahraini authorities [REUTERS]

Two ships carrying 120 Iranian activists sailed for Bahrain on Monday in an act of solidarity with the island country's Shia majority population.

The Iranian government ordered the two boats to return, while activists threw into the water letters they were carrying as "moral support" to Bahraini Shia, a journalist for Iran's English-language Press TV reported live aboard one of the vessels.

The ships turned back towards Iran at a halfway point after facing "the emergence of threats" from warships belonging to a coalition of Gulf states which have lent support to Bahrain in its crackdown on anti-government demonstrators, the Washington Post reported, citing an announcement on the activists' website.

Iranian authorities did not try to stop the ships' trip, the website said, according to the Washington Post.

Mahdi Eghrarian, an organiser of the trip, earlier told the semi-official Fars news agency that the ships had embarked at the southwestern port of Dayyer.

A third of the activists were women, 10 were children, and nobody on board was armed, Eghrarian said.

The group is carrying 5,000 letters which convey the Iranian people's "moral support", he said, for the Shia of Bahrain.

"We've started moving towards international waters. We will carry on sailing towards Bahrain's borders as far as possible in order to be able to hand over letters and messages of the Iranian nation to the Bahraini nation," Eghrarian said according to Fars.

Last month, Iranian authorities stopped two boats carrying Iranian students from leaving the southern port city of Bushehr for Bahrain in a similar show of solidarity.

Bahrain, a tiny island country in the Gulf, has a majority Shia population but is ruled by a Sunni king, who has cracked down on dissent since pro-democracy protests broke out in February.

Source: Agencies