The government in Bahrain has admitted that excessive force was used earlier this year against pro-democracy demonstrators and says 20 officers are being prosecuted for the crackdown.

More than 40 people were reported killed in March when security forces, aided by troops from Saudi Arabia and the United Arab Emirates, drove anti-government protesters out of Pearl Square in Manama, Bahrain's capital. Hundreds more were injured, dozens more arrested.

A Bahraini government statement issued on Monday said, “Regrettably, there have been instances of excessive force and mistreatment of detainees,” which it said was a violation of government policy.

The statement was issued in advance of Wednesday's publication of a report from Bahrain's Independent Commission of Inquiry into what were described as “mistakes by the state and its apparatus.”

More protests against the Sunni-led government have been reported this month in mainly Shiite areas of the Gulf nation. In one instance, a teenage boy was killed.

His death and the anticipated release of the commission report have raised fears of further anti-government demonstrations.