Riyadh: Authorities in Saudi Arabia say a police officer working on a traffic patrol has been shot dead in the kingdom’s predominantly Shiite east.

The Interior Ministry said the officer, identified as Faisal Al Harbi, was killed by unknown assailants early Friday morning in the city of Saihat. It said an investigation was ongoing.

The east has been tense since the January execution of a antigovernment Shiite cleric Nimr Al Nimr, which sparked a diplomatic crisis between Iran and Saudi Arabia with many Arab countries cutting or downgrading ties with Tehran.

Bahrain has also been cracking down on antigovernment leaders intensifying existing regional tensions.

Manama has stripped citizenship of Shiite cleric Eisa Al Qassim as well as members of a Daesh cell in the country, in a move aimed at preventing further sedition in the country.

Many Arab states across the region have long complained that Iranian interference in their domestic affairs is fomenting sectarianism and sedition.

On Thursday, a wanted man was killed in Saudi Arabia’s Eastern province after an exchange of gunfire while police were searching his home.

Saudi state news agency SPA said security forces came under heavy fire when they raided the home of Abdul Rahim Al Faraj and his brother, Majid, who was also wanted by security forces, in Awamiya on Wednesday evening.

The agency said the two brothers had been wanted for firing on security forces in attacks that killed several people and for being involved in armed robberies, and that weapons had been found in the house.

Awamiya is also the hometown of Al Nimr. In February, Saudi security forces killed Ali Mahmoud Ali Abdullah, a Bahraini national, who was wanted for taking part in “terrorist crimes”, according to the ministry.

Qatif in Eastern province has been the focal point of unrest among Saudi Arabia’s Shiites since protests in early 2011.