A Bahraini court has jailed a journalist for three months over a tweet deemed insulting to religion, Reporters Without Borders said Wednesday.

Faisal Hayyat, a journalist and a blogger who hosts a satirical channel on YouTube, was convicted Tuesday of insulting a "religious symbol and group", the watchdog said.

He has been in detention since Oct 9, the last time he tweeted saying that he had been summoned by police for investigation.

The content of the tweet that the charges refer to is not clear, but on October 8, Hayyat posted tweets denouncing Muawiyah, the first caliph of the 7th-century Umayyad Caliphate.

The Gulf kingdom has been shaken by unrest since security forces crushed protests led by crowds of its Shia majority demanding a constitutional monarchy and an elected prime minister in 2011.

Scores of Shia people have been jailed on charges of involvement in the unrest and others have been stripped of their citizenship.

The crackdown has drawn criticism from the United Nations and the United States.