Two Saudi security officers and two people said to be wanted by the authorities have been killed in a gunfight in the eastern town of al-Awamiya, an area where the country’s Shia minority have staged regular anti-government protests.
An Interior Ministry spokesman said security forces came under fire while trying to arrest "a number of armed troublemakers" who had previously fired on residents and security forces in Awamiya, according to state news agency SPA.
"As a result of the exchange of fire, the wanted men Ali Ahmed al-Faraj and Hussein Ali Madan al-Faraj were killed," SPA said, adding that two security men had also died and two more were wounded.
It said two pieces of weapons, a bullet-proof vest, a pair of binoculars used by snipers and a large amount of ammunition were found at the scene.
The agency quoted the ministry as saying that the security forces responded to the source of shooting in accordance with standing rules.
Local activists denied that there was any exchange of fire at the scene and said security forces burst into the house of a man in search of his wanted brother who was not there, Reuters news agency reported.
Shia Muslims in the region complain of discrimination, a charge denied by Sunni Muslim-ruled Saudi Arabia, the world's largest oil exporter, and the Riyadh government blames Shia-led neighbour Iran for the rise in tensions.
At least 21 people have been shot dead in the region since early 2011, when Shias there staged protests against the involvement of Saudi forces in ending demonstrations in neighbouring Sunni-ruled Bahrain, which has a Shia majority.
In 2012, Saudi Arabia ordered the arrest of 23 Shias in the eastern province, saying they were responsible for the unrest.
On Wednesday a court in Riyadh sentenced seven men to between six and 20 years in jail on offences that included taking part in protests in the town of Qatif.
The SPA news agency said the seven had been also convicted of chanting slogans against the kingdom as well as possessing and making petrol bombs and hurling them at security forces.