Bahraini rights activist Nabeel Rajab denied bail

A Bahraini court denied bail for prominent human rights activist Nabeel Rajab as he went on trial on charges of insulting a state institution and neighbouring Saudi Arabia online, his group said on Wednesday.

The 51-year-old activist, who had been pardoned for health reasons last year, was rearrested last month as part of an intensifying crackdown on government critics that has drawn protests from the United Nations and key ally the United States.

Rajab appeared in court on Tuesday and was charged with "insulting a statutory body, insulting a neighbouring country and disseminating false rumours in time of war," the Bahrain Centre for Human Rights said.

The accusations refer to tweets posted on his account in 2015, referring to "allegation of torture" at Bahrain's Jaw prison, and the Saudi-led military intervention in Yemen, the BCHR said.

Rajab has had recurring health problems and was briefly hospitalised late last month but the court ordered that he remain in custody throughout the trial and set the next hearing for August 2.

Amnesty International has said Rajab could face up to 13 years if convicted and has slammed what it described as a "farcical trial."

The Shia activist has been repeatedly detained for organising protests and publishing tweets deemed insulting to Bahrain's Sunni authorities.

He previously served two years in jail on charges of taking part in unauthorised protests in the Shia-majority kingdom.

Home to the US Navy's Fifth Fleet, Bahrain has been rocked by unrest since security forces crushed Shia-led protests in 2011 demanding a constitutional monarchy and an elected prime minister.