But Prince Salman, who has long been regarded as a moderate voice within the Gulf state’s Sunni minority regime, said he was “optimistic” a settlement could be reached with the Shiite-led opposition.

“I’m optimistic that a solution will be found here,” the prince told reporters at the desert Sakhir circuit, south of the capital Manama, as qualification for today’s race passed off without incident.

Hundreds took to the streets in Shiite villages outside Manama overnight, prompting clashes with police, but away from the circuit, witnesses said.