Saudi security forces killed two men who opened fire on police during a raid on a farm in eastern Saudi Arabia used by militants to plot and prepare for attacks, the interior ministry said on Wednesday.

The Mokhtar Brigades, a little known militant group based in neighboring Bahrain, identified the two men as Meqdad al-Nimr and Mohammed al-Nimr, describing them as “martyrs”.

Also, four other Saudis were arrested following the clash yesterday morning, the ministry said in a statement carried by state news agency SPA.

Those arrested were reported to be Abdelrahman Fadel Abdallah al-Abdalaal, Mohammad Jaafar Abdallah al-Abdalaal, Jaafar Mohammad AlFarj, and Wasfi Ali Makki al-Qaroos.

The statement confirmed that all those killed and arrested were “Saudis who have previous precedents to have been linked and involved in terrorist acts and criminal attacks, no citizens or security forces were injured in the operation.”

SPA said security forces came under fire while conducting a search in a farm outside the town of Awamiya.

“The source of gun fire was dealt with immediately and neutralized and the mission was completed successfully,” the statement said, adding that four other people with a history of involvement in “terrorist and criminal acts” had been arrested.

No policemen or innocent citizens were hurt in the raid, it said.

Photos were circulated of one of the two men with two bullet holes in the back and one in the head.

After searching both farms, security forces found 130 gallons of burning acid, bomb building materials, a gallon of potassium, three machine gun storage areas, seventy-one rounds of ammunition and a black mask.