A soldier has been shot dead and another injured during a clash with protesters in eastern Saudi Arabia, according to state media.
An interior ministry spokesman said that a security patrol was fired at by rioters on a motorbike in Qatif.
A protester was also killed in a firefight following the incident, according to news agency AFP.
The oil-rich Eastern Province is home to a Shia majority that has long complained of marginalisation.
Speaking to state media, Interior Ministry spokesman Mansour al-Turki said the shooting took place at 11pm on Friday evening.
"A security patrol was exposed to heavy fire from four armed rioters on a motorbike when pausing at a street intersection in Qatif", he is reported to have said.
He named the dead soldier as Hussein Bawah Ali Zabani and the wounded soldier, who was taken to hospital, as Saad Miteb Mohammed al-Shammari.
AFP quotes Mansour al-Turki as saying a "rioter" had been killed in a firefight following the incident.
Last week, state media said security forces detained a number of protesters in Qatif after tyres were set on fire during an overnight demonstration.
Protests erupted in the region in March 2011 when a popular uprising in neighbouring Bahrain, which has a Shia majority and a Sunni royal family, was crushed with the assistance of Saudi and other Gulf troops.