Saudi Arabia said two security personnel were killed in nationwide arrest raids after gunmen attacked a Shiite religious celebration in the oil-rich east.

Arrests took place in six cities yesterday, and the security force members were killed while detaining suspects in Buraidah in the central Qassim region, the official Saudi Press Agency said, citing an Interior Ministry spokesman it didn’t identify. Two suspects were also killed, and a total of 20 are being held, according to Saudi-owned Al Arabiya television.

The operation followed a Nov. 3 attack by masked gunmen against Shiites in the village of al-Dalwah, hundreds of miles east of Buraidah. Al Arabiya said the death in the village rose to seven, with 10 people wounded. […]