Bahrain riot police have fired tear gas and stun grenades at Shia protesters who threw petrol bombs during a demonstration against Sunday’s Formula 1 race.

Bahrain riot police have fired tear gas and stun grenades at Shia protesters who threw petrol bombs during a demonstration against Sunday’s Formula 1 race, witnesses told Agence France Presse.

Protesters shouted "your race is a crime" as they marched through the streets of Shia districts. Graffiti on nearby walls read, “No F1. Don’t race on our blood.” Bahrain's main opposition bloc has called for peaceful pro-democracy demonstrations to be stepped up before the race.

"There are many protests against Formula 1 in Bahrain. They have blocked the roads which lead to the F1, as well as roads close to the American base and the bridge between the airport and the capital Manama," Acting Vice President of the Bahrain Center for Human Rights, Yousif Almuhafdah, told RT news website.

The February 14 Revolution Youth Coalition, a cyber group that organizes protesters, boasted on its Twitter account that people took to the streets with "a steel will."

The group added that people were "imposing a different rhythm in the street, in the first round of Volcanos of Flames" - referring to the name they have given to a week of demonstrations against the F1 race.

The country’s state news agency said late Wednesday that authorities arrested four people for allegedly stealing and burning a car near a roundabout. An additional person was detained over an accusation that he blocked a main road and caused damage to another person’s car.

Human rights activists have claimed dozens of anti-government protesters have been arrested prior to the race, according to Amnesty International.

The organization has accused authorities of using the race as a platform to “show progress, with claims that the human rights situation has improved, whilst stepping up repression in order to ensure nothing disturbs their public image.”

“We are seeing nothing but crackdowns and token gestures to clean up the country’s image,” Amnesty International’s Middle East and North Africa Program deputy director, Hassiba Hadj Sahraoui, said in a Wednesday statement.

Human Rights Watch said last week that police had arrested 20 opposition activists in towns near the F1 circuit.

The organization said the arrests were made with the intention of preventing a repeat of the 2012 F1 protests. Last year’s race went ahead against a backdrop of burning tires and riot police firing teargas at protesters throwing petrol bombs in the villages.

The 2011 Bahrain race was canceled when protests were crushed and at least 35 people were killed.

At least 82 people have been killed and thousands arrested since the unrest began. Many opposition figures have been detained on the allegation of planning to topple the government.