Authorities in Bahrain have opened an investigation after the body of a man was found near the scene of clashes between protesters and the security forces.
Opposition groups claimed the man was killed by riot police in another possible blow to the Gulf nation as it struggled to quell unrest during the highly awaited return of the Formula One Grand Prix.
A statement by Bahrain's Interior Ministry said a probe was under way. Officials said the man who died was identified as Salah Abbas Habib Musa, 36, and the case was "being treated as a homicide". The ministry statement did not give a cause of death but said investigators found "a wound" on the left side of his body.
At least 50 people have died in the unrest since February 2011 in the longest-running street battles of the Arab Spring. Bahrain's Shiite majority seeks to break the near monopoly on power by the ruling Sunni dynasty, which has close ties to the West.
The body was found in an area west of the capital Manama about 12 miles from the racing circuit. Clashes broke out in the area after a massive protest march on Friday. Social media sites have urged more demonstrations as part of the opposition's effort to use the world spotlight from the race to press their demands for a greater political voice.
The protests have left the country's rulers struggling to keep attention on the build up to the F1 race - Bahrain's premier international event. It was called off last year amid security fears and Bahrain's leaders lobbied hard to hold this year's event in efforts to portray stability and mend the country's international image.
But protesters had also seized on the worldwide attention since race teams and fans began arriving this week.
"We demand democracy," and, "Down, Down Hamad," chanted some of the tens of thousands of opposition supporters on Friday in reference to King Hamad bin Isa Al Khalifa, as they massed on the main road leading out of Manama. Bahrain's monarchy is the main backer of the F1 race, and the crown prince owns the rights to the event.
Hours before the march, Bahrain's most senior Shiite cleric, Sheik Isa Qassim, delivered a strongly worded sermon that denounced authorities for making dozens of arrests of suspected dissidents in recent weeks. He called the intensified crackdowns before the F1 event were "as if we are entering a war" in the kingdom.
Shiites account for about 70% of Bahrain's population of just over half a million people, but claim they face widespread discrimination and lack opportunities granted to the Sunni minority. The country's leaders have offered some reforms, but the opposition says they fall short of Shiite demands for a greater voice in the country's affairs and an elected government.