BAGHDAD: Iraq has freed around 400 prisoners since Sunni Arabs began anti-government demonstrations last month, and will press on with more releases on a daily basis, a top minister said on Wednesday.

Deputy Prime Minister Hussein al-Shahristani said that a committee formed in the wake of the protests would accelerate the process of reviewing prisoners' cases and would look to immediately release those who had been proven innocent.

Thousands of demonstrators have been rallying in Sunni-dominated areas of Iraq for more than three weeks, protesting the alleged abuse of anti-terror laws by the Shiite-led authorities and demanding the release of prisoners they say were unfairly arrested.

"The release of detainees will continue on daily basis, not just for media purposes," Shahristani told a news conference in Baghdad.

But, he added, "the demonstrations alerted us to the presence of a defect."

Shahristani said authorities had released 70 prisoners on Wednesday, bringing to more than 400 the number of detainees freed in recent weeks.

Officials have not provided any breakdown of the prisoners, and have not given details on how many had finished jail terms and how many had been held without charge.

Shahristani's latest news conference comes two days after he publicly apologised for detainees being held without charge, part of efforts to curb the ongoing rallies.

Anti-government rallies have been ongoing since December 23 in mostly Sunni areas of Iraq, with the longest-running of the protests blocking off a key highway linking Baghdad to Jordan and Syria.