Saudi Arabia said today it has foiled a bomb plot by the Islamic State group and blamed the jihadists for shooting dead two policemen in the capital earlier this month.
The authorities said three bomb-laden cars had been seized during investigations into the killings.
A Saudi man arrested on suspicion of carrying out the shooting has confessed that he was following orders received from IS in Syria, the interior ministry said.
He was identified as 23-year-old Yazid bin Mohammed Abdulrahman Abu Niyan.
The authorities offered a one-million-riyal ($267,000, 246,220-euro) bounty for a second suspect, another Saudi identified as Nawaf bin Sharif Samir al-Anzi.
During their investigation the authorities seized seven cars, "three of them booby-trapped", as well as suspected bomb-making materials and tools, said the statement carried by the official Saudi Press Agency.
They also discovered machineguns, ammunition, money and several mobile telephones which revealed an exchange between the attackers and "terrorist elements in Syria", SPA said.
The two policemen were killed in an April 8 drive-by shooting in an eastern district of Riyadh.
The ministry said that Abu Niyan allegedly carried out the shooting while his partner, Anzi, drove the car and filmed the attack.
According to Abu Niyan, IS supplied them with the weapons, ammunition and money to carry out the shooting through a "third party whom they did not meet", the statement said.
The Sunni-dominated kingdom is part of a US-led coalition taking part in an air war against IS, which has seized swathes of Syria and Iraq.
Westerners have been attacked in Saudi Arabia four times since October, including in a drive-by shooting that wounded a Dane in Riyadh on November 22.
Authorities later arrested three suspected IS supporters.
Today's statement also said that in the coming days the authorities will give details of a series of other "security incidents" that have been uncovered and foiled.
