MANAMA — Riot police in Bahrain fired tear gas Friday to disperse several hundred protesters among thousands who took to the streets Friday to demand the government's resignation after a fact-finding report uncovered torture and other abuses against detainees.

The protesters carried the Bahraini flag as they marched for nearly six kilometres along a highway through Shiite neighbourhoods in a northern district of the island kingdom. After the march, several hundred protesters gathered at a traffic circle, prompting police to seal off the road and release clouds of tear gas.

Bahrain's Shiites, about 70 per cent of the nation's 525,000 citizens, complain of widespread discrimination under the kingdom's Sunni rulers, including being blocked from top government or military posts. The monarchy has offered some concessions but refused to bow to demands for greater political freedoms and rights.

Activists accuse the government of failing to implement the recommendations of a fact-finding mission it authorised. The mission's 500-page report, released in November, found a number of detainees were tortured as "a deliberate practice by some" during the height of the protests in February and March.

"No change has happened," said Fatima Ahmad, a 24-year-old protester. "All the officers and people who were involved in the violation of human rights were awarded different posts and positions. The government is fooling its own nation and that is why it must resign."

The report on the crackdown was also highly critical of a special security court created under martial law that issued harsh penalties, including death sentences, and "denied most defendants elementary fair trial guarantees."

Bahrain lifted martial law in June and dissolved the security court.

The report urged Bahrain to review all the security court verdicts and drop charges against those accused of nonviolent acts such as joining or supporting the protests.

Five Shiite opposition groups, including the country's largest, Al Wefaq, said in a statement Friday that the government has no intention of taking steps recommended by the report.

"The regime has demonstrated a lack of seriousness for carrying out (the) recommendations," it said.

Marchers on Friday called for the release of political prisoners, some of whom were tried by the special security court, and for the trials of police officers believed to be behind the killings of more than 35 protesters since anti-government protests began 10 months ago.

On Thursday, the country's Information Affairs Authority said five police officers will be put on trial in connection with the alleged torture of a detainee who later died in custody.

Student Mohammed Ali said the current government has no credibility and must resign.

The protesters, though, have not called for the downfall of the Sunni-led monarchy, which reshuffled the government this year under pressure from activists.

Early Friday, the Interior Ministry said police arrested 80 people in the eastern village of Nuwaidrat who allegedly attacked a police patrol with fire bombs.