DUBAI (Reuters) - An off-duty policeman was shot dead in Bahrain on Sunday in what the interior ministry called a “terrorist act,” state news agency BNA reported.

The shooting follows increased unrest in the Sunni Muslim-ruled kingdom after the execution this month of three Shi’ites convicted of killing three policemen in a bomb attack in 2014.

“The Interior Ministry mourns with great sadness and sorrow the martyr Lieutenant Hisham Hassan Mohammed al-Hammadi, who was shot and killed in the Bilad al-Qadeem area,” southwest of the capital Manama, the interior ministry said.

“Initial indications suggest that it was a terrorist act and that he was not on duty.”

Mass “Arab Spring” demonstrations in 2011 led by the island’s Shi’ites were crushed by the authorities with help from Gulf Arab neighbors, deepening sectarian rivalry in the region.