DUBAI: At least 10 civilians and several policemen were injured in Bahrain on Thursday, an opposition group and the government said, during protests to mark the second anniversary of the arrival of Saudi forces which helped crush a pro-democracy uprising.

Home to the U.S. Fifth Fleet, the tiny state has been hit by unrest since the revolt in early 2011, becoming a front line in a region-wide tussle for influence between Shi'ite Muslim Iran and Sunni Arab states such as Saudi Arabia.

Saudi Arabia and the United Arab Emirates sent in 1,500 troops on March 14, 2011 to help suppress the uprising.

The mass disturbances were crushed but demonstrators, mainly from Bahrain's Shi'ite majority, have continued small protests on an almost daily basis demanding equality and a constitutional monarchy in the kingdom ruled by the Sunni al-Khalifa family.

The latest violence followed the death of two young men during clashes with police last month as Bahrainis marked the second anniversary of the Feb. 14 start of the uprising. It is likely to cast a shadow over reconciliation talks between the government and the opposition aimed at ending political turmoil.

The Islamist Wefaq association - the country's biggest opposition group - said that, by midday on Thursday, at least 10 people had been injured by security forces who they said used live bullets, birdshot and teargas against "peaceful demonstrators".

Three of those injured were in critical condition, the group said in a report on its website. It posted pictures of injuries, including a limb hit by what appeared to be a live round.

The Information Affairs Authority said several policemen were injured when demonstrators attacked them with petrol bombs and iron rods, and detonated homemade bombs "endangering the lives of innocent bystanders and security personnel".

"Police used restraint to restore order and all force used was necessary and proportionate," the assistant chief of security for operations said in the statement.

The statement said the demonstrators had stolen cars, torched vehicles and blocked the streets with large rocks and lampposts and scattered nails and oil on roads. It attached pictures of barricaded roads and torched vehicles.

It was not immediately possible to verify the authenticity of the reports or pictures given by either side.

An international inquiry commission, invited by Bahrain's government, said in a report in November 2011 that 35 people had died during the uprising. The dead were mainly protesters but included five security personnel and seven foreigners. The report said five people had died from torture.

The opposition puts the death toll at more than 80.

Bahrain's opposition and government resumed reconciliation talks last month for the first time since July 2011, but little progress has been reported in several sessions of negotiations.