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

A Bahraini court denied bail for prominent human rights activist Nabeel Rajab as he went on trial on charges of allegedly insulting a state institution and neighboring Saudi Arabia online, his group said 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 opposition figures that has drawn protests from the United Nations and key ally the United States.

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

Rajab has had recurring health problems and was briefly hospitalized 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 the farcical trial.

The Bahraini opposition has been confronting the regime's oppression and repressive measure since 2011 when a wide revolution erupted across the country, demanding that the authorities grant all the citizens their basic political and social rights.