A state-appointed commission probing rights abuses in Bahrain said on Tuesday it had closed its office to visitors bringing in complaints after protesters mobbed it over misleading reports that the panel had cleared government officials of wrongdoing.

Bahrain's king invited the panel, headed by international law professor Cherif Bassiouni, to examine charges of widespread torture and abuse by security forces during two months of martial law after pro-democracy unrest was suppressed.

Recent comments by Bassiouni praising the cooperation of the interior minister and saying he could see no policy of excessive use of force or torture infuriated majority Shi'ite Muslims, who dominated the protests and bore the brunt of the crackdown.

"Hundreds of people forced their way into our office, having been angered over what they believed to be the Commission Chair's 'conclusions' in the investigation," the panel said.

"After attempting to accommodate the crowd by offering to take down their information in order to schedule appointments, some in the crowd became restless and verbally and physically threatened the staff," it said in a statement.

"Individuals yelled insults, posted threatening messages on the office walls, sent threats via text and email, and even physically shoved and spat at a member of staff."

The panel said it would continue to accept statements submitted by email but would stop granting media interviews to avoid being used as a "political tool" by any group.

The official Bahrain News Agency had reported on Monday that the commission believed no "crimes against humanity" had been committed after Bassiouni was quoted in a newspaper interview saying torture claims would require proof.

Activists then urged hundreds of Bahrainis fighting to get their jobs back after they were sacked during martial law to gather at the commission headquarters.

The activist group, called "Return To Work Is My Right", said on Tuesday it would investigate the incident but defended the decision to congregate at the offices, saying the commission was their last hope after the government had ignored them.

The government in the island state, ruled by the Sunni Muslim al-Khalifa family, said the democracy movement was sectarian in origin and backed by Shi'ite power Iran across the Gulf.

Bahrain is home to the U.S. Fifth Fleet and its Shi'ites are regarded by Saudi Arabia, which sent in troops to help quell the protests, as a soft target for Iranian influence.

King Hamad bin Isa al-Khalifa last month approved some parliamentary reforms that would give the elected chamber more powers of oversight but not lessen the powers of an appointed upper house or allow political parties to form governments.

Those reforms were the result of a national dialogue established to address some of the complaints of protesters, who were inspired by the popular uprisings in Egypt and Tunisia.

The main opposition parties pulled out of the dialogue, focusing attention on Bassiouni's commission as the next hope of democrats to act as a catalyst of change in the country.