Bahraini officials have apologized over police taking down Shiite banners and flags marking Ashoura, an action that sparked clashes earlier in the day in the island kingdom.

The Shiite opposition group al-Wefaq says several people were injured in the clashes outside of Manama on Tuesday. Authorities gave no casualty figures for the clashes, which saw police fire tear gas and birdshot.

The kingdom's Shiite Endowment Department later issued a statement acknowledging the banners and flags were allowed and said their removal "contradicted the guidelines" of the king.

Ashoura is a Shiite Muslim commemoration marking the death of Hussein, the Prophet Muhammad's grandson, at the Battle of Karbala in present-day Iraq.

Bahrain has been rocked by years of turmoil between its Sunni rulers and largely Shiite population since 2011.