Unrest simmers ahead of Bahrain Grand Prix

Bahrain riot police fired tear gas and stun grenades at anti-government activists on Thursday and members of the Force India race team were caught up in a petrol bomb incident as unrest simmered ahead of this weekend's Formula One Grand Prix.

Protesters seeking to oust Bahrain's monarchy have threatened "days of rage" to coincide with the race meeting, while organisers have ignored appeals to call off an event that was cancelled last year due to violent demonstrations during the Arab Spring.

The organisers' decision to go ahead with the highly lucrative race has put increased pressure on sponsors, whose critics say they are backing a glitzy sporting spectacle taking place against a background of political repression.

While international sports correspondents are in Bahrain for the race, non-sports reporters from some other news organisations have not been granted visas to visit the Gulf island.

Several hundred people tried to stage a protest in the capital, Manama, on Thursday. The protesters moved from a Shi'ite neighbourhood in the back streets chanting slogans against the government but riot police fired tear gas and stun grenades when they tried to enter a main highway near the British embassy.

Bahrain's chief of public security said a number of "rioters and vandals" had been arrested for taking part in unlawful protests.

Bahrain has been in turmoil since a democracy movement erupted more than a year ago after uprisings in Egypt and Tunisia. Protests were initially crushed with the loss of dozens of lives but youths still clash with riot police and thousands take part in opposition rallies.

Western companies are opting not to entertain clients and partners at the race following calls for sponsors to boycott the event because of the political turmoil.

Shell, which sponsors the Ferrari team, will not be hosting any guests at the event, a source familiar with the company's plans said.

For Bahrain's al-Khalifa family - a Sunni Muslim dynasty ruling a majority Shi'ite population and caught between powerful neighbours Saudi Arabia and Iran - this year's race has been an opportunity to tell the world that all is back to normal.

But with demonstrations taking place daily, two members of the British-based Force India team asked to go home after the petrol bomb scare.

The Bahrain race circuit said four members of the team travelling between the track and the capital, Manama, drove through "an isolated incident involving a handful of illegal protesters acting violently towards police".

"During this incident a Molotov cocktail landed in the vicinity of their vehicle," a statement said.

Force India, whose drivers are Germany's Nico Hulkenberg and Britain's Paul Di Resta, said they had not been a target of the violence and no one in the team was hurt.

Although only one petrol bomb was mentioned by a team spokesman, sources indicated there may have been several more that landed on the highway to Manama on Wednesday evening during clashes in a nearby village between anti-government protestors and police.