ABU DHABI: The daughter of a prominent Bahraini opposition activist and 40 other people were arrested early on Friday, hours after security forces used tear gas and birdshot to disperse hundreds of protesters demanding political reforms, activists said.

At least 45 people were injured in the security forces' operation to break up the three separate protests across the Gulf Arab island kingdom late on Thursday, they said.

Bahrain crushed an uprising led by majority Shi'ite Muslims last year, after successful popular revolts in Tunisia and Egypt, but protest marches and rallies continue, leading at times to clashes between police and Shi'ite youths.

Bahraini Shi'ites say they have long been marginalised in political and economic life, which the government denies. Bahrain's Sunni rulers have rejected the main opposition demand - an elected parliament with full powers to pass laws and form governments.

The head of the Bahrain Youth Society for Human Rights, Mohammed al-Maskati, said activist Zainab al-Khawaja was arrested early on Friday when she tried to hold a solitary protest sit-in at al-Badei street close to the capital Manama.

Zainab is the daughter of Abdulhadi al-Khawaja, a leading Shi'ite figure in the uprising who ended a more than three-month-long hunger strike in May after drawing attention to the issue of imprisoned activists.

"She had taken part in the protests and then headed to that street to start a sit-in. That is when she was arrested," Maskati told Reuters by telephone.

"From the information we have managed to gather from lawyers and the families of protesters, at least 40 others have been arrested as well," he said, adding that police had used tear gas to disperse the protesters. There were no reports of serious injuries.

"All three protests were heavily crushed as tear gas and birdshot was used with reports of at least 40 to 45 people being injured," Maskati said, adding that injuries ranged from slight to serious.

Government officials were not immediately available for comment.

The Interior Ministry said in a statement on its website that "riot instigators" threw Molotov cocktails at a ministry vehicle in a road near Bani Jamra, but that its driver and his companion escaped uninjured. AGENCIES