An explosion wounded a policeman in a Shiite village near Bahrain's capital, where protesters demonstrating against the ruling Sunni monarchy had blocked roads, the interior ministry said.

Clashes frequently erupt on the outskirts of Manama between security forces and protesters from the country's Shiite majority demanding Bahrain's ruling Sunni Khalifa family surrender its grip on all key cabinet posts in favor of an elected government.

"Police had confronted a group of saboteurs who blocked roads in the village of Akr al-Sharqi," the ministry said in a statement late Sunday.

A policeman trying to "help a woman cross a road" was "lightly wounded" in the explosion, which damaged a police vehicle and a civilian vehicle, the statement said, without giving further details.