Human Rights Watch said police have arrested 20 opposition activists in towns near Bahrain’s Formula One circuit in a sign of rising political tension before the Grand Prix on 21 April.
The Bahrain government denied any arrests had taken place.
The Gulf state, where the US navy’s Fifth Fleet is based, has been hit by unrest since pro-democracy protests broke out in 2011, putting it in the frontline of the tussle between Shiite Muslim Iran and Sunni Arab states such as Saudi Arabia.
The Grand Prix is the biggest sporting event hosted by the country and the government is hoping for a big turnout at this year’s event despite continuing violent unrest.
An HRW statement said the detentions were made with the apparent intention of preventing a repeat of violent protests during last year’s race.