Mercedes Formula One driver Nico Rosberg of Germany drives in the pit lane during the third practice session of the Bahrain F1 Grand Prix at the Sakhir circuit in Manama April 21, 2012.
A Bahraini protester was found dead after clashes with riot police on Saturday, the eve of the Gulf kingdom's Formula One Grand Prix that anti-government activists have vowed to mark with "days of rage".
The opposition party Wefaq said the body of a man named as Salah Abbas Habib, 37, was found on the roof of a building in a rural village. It said the protester was part of a group who were beaten by police.
Wefaq, the leading party among Bahrain's restive Shi'ite Muslim majority population, published a photograph taken of Mr. Habib's body splayed on a corrugated iron rooftop.
Bahrain's Interior Ministry said via Twitter that it was launching an investigation.
Dozens of armoured vehicles and security forces in riot gear were deployed along the road to the Bahrain International Circuit and around the capital Manama. Activists said barbed wire has been installed near some parts of the main highway.
The protesters, mostly from the majority Shi'ite Muslim community, blame the Sunni ruling elite for shutting them out of opportunities, jobs and housing. They have made it clear they will use the international attention the motor race has focused on Bahrain to air their grievances.
"The government are using the Formula One race to serve their PR campaign," said rights activist Nabeel Rajab. "It's not turning out the way they wanted."
There were no protesters near the Grand Prix circuit, which was blanketed with layers of security. Saturday's practice runs began without incident.
Organizers have rejected calls from human rights groups to cancel Sunday's race because of what activists see as continuing political repression.
"They need to fix the country first, then they can start looking at Formula One and other events," said Umm Hussein, one of 10,000 demonstrators who gathered near Manama on Friday.
Police used teargas against masked youths throwing petrol bombs, who were trying to reach a traffic roundabout that was a rallying point during an uprising last year inspired by the Arab Spring revolts that toppled the presidents of Tunisia and Egypt.
Opposition leaders said they are not planning any organized mass rallies on Saturday, but did not rule out gatherings later in the day that might grow in size.
Last year's race was delayed, and then cancelled, after a brutal crackdown against pro-democracy protesters in Bahrain, a financial hub and modest oil producer that is also host to the Fifth Fleet, the U.S. Navy's main outpost in the region.
Security forces from neighbouring Saudi Arabia came in, the streets were cleared and 35 people, including security personnel, died.
Since then, amid simmering unrest, Bahrain has invited in an independent commission to prescribe reforms and has enacted some, but human rights groups say there is still more work to be done. They say the kingdom's rulers are using the motor race to improve their international image.
"We are committed to our programme of reforms, but this week's unbalanced coverage does little to help the progress we are already making," a Bahrain Information Affairs Authority official said in a statement.
While sports journalists poured in to cover the race, non-sports reporters from Reuters and some other news organizations have not been granted visas to visit the Gulf island.
Hackers brought down the F1 website intermittently on Friday and defaced another site, f1-racers.net, to support what they described as the Bahraini people's struggle against oppression.
At stake is an event that has cost Bahrain an estimated $40 million to stage, drawn more than 100,000 visitors and generated more than $500 million in spending.
The pride of Bahrain's ruling royal family is also under threat. It was Crown Prince Sheikh Salman bin Hamad al-Khalifa who brought the race to the country in 2004, securing the first Formula One event in the region.
Two of the 12 teams were left rattled after witnessing protesters throwing petrol bombs. Two members of the Force India team went home to Britain although the other team, Sauber, continued with race preparations.
Force India returned to the track after skipping the second practice sessions on Friday. Qualifying races were scheduled for the afternoon, before the main race on Sunday.
Formula One chief Bernie Ecclestone described general security fears as "nonsense".
Team principals echoed the sentiment, saying they were confident in security measures, which they said were similar to arrangements seen at other Formula One races across the globe.
Of particular concern to security forces are young Bahraini protesters carrying petrol bombs who clash with police in Shi'ite villages surrounding the capital nearly every night.
Opposition leaders say around 95 protest organizers have been arrested in night raids in the past week and 54 people wounded in clashes, in which police have fired birdshot.
Also of concern is the health of hunger striker Abdulhadi al-Khawaja, one of 14 men in prison for leading an uprising last year.
Mr. Khawaja's family said he stopped drinking water on Friday, after being on hunger strike for more than 70 days. His death would be a major blow to the government, which is trying to make the case that reforms are under way.
His release, however, would also be a loss of face and could energize the opposition. Denmark, where Mr. Khawaja also holds citizenship, has offered to take him.
"His situation is very dangerous," said activist Mr. Rajab. "If he dies that will make people very angry."
Instrumental in founding found the Bahrain Centre for Human Rights, Mr. Khawaja is one of eight serving life sentences after he expressed support last year for Bahrain becoming a republic.