Two people have been killed in a suicide bombing at a mosque in the Saudi city of Najran that was claimed by the Islamic State group, which has repeatedly targeted Shi'ites in the Sunni-ruled kingdom.
The attack occurred just after Maghrib early evening prayers on Monday at the Al-Mashad mosque in the southern city's Dahza neighbourhood, said the Saudi interior ministry.
The IS jihadist group claimed responsibility for the attack on what it said was an Ismaili Shi'ite mosque, said SITE Intelligence Group, a US monitoring organisation.
Al-Hijaz Province, a group affiliated to IS, said on Twitter that a fighter named Abu Ishaq al-Hijazi detonated his explosive belt at the mosque, causing "many" casualties.
In their statement, the group said the assailant "detonated his explosive belt in an assembly of the rejectionist Ismaili polytheists".
In August, the same group claimed another blast in Saudi Arabia's southern region.
Fifteen people died in that suicide bombing at a mosque frequented by members of a police special weapons and tactics unit in Abha city.
"As worshippers were leaving the mosque, a person wearing a suicide belt entered and blew himself up amongst them," the ministry said of the latest attack.
It said one person was killed at the scene and a second died later of injuries. The wounded were taken to hospital, it said without giving a number.
Saudi news channel Al-Ekhbariya earlier said that apart from the initial death, 12 people were wounded. It had also reported that the attacker was wounded.
On its Twitter account, the ministry said investigators found a vehicle belonging to the bomber.
The vehicle contained a letter to his parents about his crime, the ministry added.