Thousands of Bahrainis have rallied for reform in Bahrain as an international panel set up by the king began to investigate Shi'ite-led protests and a government response that left more than 30 people dead.

Some of the rallies late Monday urged action against kingdom officials who protesters say suppressed peaceful demonstrations.

The head of the five-member panel said Sunday his team would meet with government officials and opposition voices to investigate the protests.

Bassiouni said his team also will look at the role of security forces in putting down demonstrations through force and arrests.

The panel expects to report its findings in October.

Bahrain's Sunni rulers imposed martial law and crushed weeks of pro-democracy protests led mostly by majority Shi'ites in March. The state of emergency was lifted June 1.

At least 32 people were killed during the crackdown, hundreds were arrested – mostly Shi'ites – and 2,000 were dismissed or suspended from their jobs.

Bahrain has said it will give the commission access to official files and allow it to meet witnesses in secret. The government in Manama denies any systematic abuse by police.

Instead, it has accused protesters of pursuing a sectarian agenda backed by the neighboring Shi'ite power, Iran.