DUBAI: An explosion wounded two civilian passers-by in Bahrain, the interior ministry said early Wednesday, as demonstrators were marking the sixth anniversary of an anti-government uprising that was bloodily suppressed.

The ministry did not say what caused Tuesday evening's blast in a village outside the capital Manama but demonstrators sometimes throw petrol bombs during the sporadic protests that still grip the Sunni-ruled but Shiite-majority kingdom.

"Terrorist blast in Sitra causes minor injuries to a married couple passing the site. Police at the scene," the ministry said on its Twitter account without elaborating.

It also tweeted a picture of a black 4X4 with a shattered windscreen and significant damage to the front bonnet.

The blast came as demonstrators clashed with police in Manama and several nearby villages.

The demonstration in the capital ended when police fired tear gas and stun grenades, witnesses said.

Activists posted pictures of injured protesters online, but the interior ministry has not published any official statements about the reported demonstrations.

The Shiite-led protests of February 2011 sought a constitutional monarchy and an elected prime minister to replace the current government dominated by the ruling Al-Khalifa family.

Authorities crushed them the following month with the support of Saudi-led forces who secured key installations.

Since then, the authorities have banned the Shiite opposition and handed long jail terms to many of its leaders. Some have been stripped of their citizenship.

Tiny but strategic Bahrain lies just across the Gulf from Iran and is home to the U.S. Navy's Fifth Fleet.