Riyadh: Authorities in Saudi Arabia say security forces conducting a series of anti-terror raids have killed two suspects and arrested three.

The official Saudi Press Agency reported on Monday that the simultaneous raids targeted sites around Riyadh and in Dammam.

The Interior Ministry said those targeted in the raids belonged to an affiliate of the Daesh terror group linked to an attack in Abha, 560 kilometres south of Makkah.

The men had reached “advanced stages of preparation” in planning the attack, the ministry said in a statement carried by the official Saudi Press Agency.

On August 6, a Daesh-affiliated suicide bomber attacked a mosque inside a police compound in Abha, killing 15 people. It was the deadliest attack on the kingdom’s security forces in years.

Terrorist attacks in Saudi Arabia have increased since the government joined US-led operations against Daesh in Syria last year. Two Shiite mosques were targeted in May in the kingdom’s oil-rich eastern province, with the deadliest killing 21 worshippers. In neighbouring Kuwait, a Saudi suicide bomber targeted a Shiite mosque in July, killing 26 people.