They are angry and grief-stricken, but Saudi Arabia's minority Shiites refused on Sunday to be provoked by a deadly mosque bombing that authorities called an attempt to promote sectarian strife.

King Salman vowed punishment for anyone linked to the "heinous crime," which killed 21 people.

The interior ministry confirmed the identity of the suicide bomber who blew himself up inside a Shiite mosque in Eastern Province on Friday and said he had links with Daesh jihadist group.

It was the deadliest assault in years on the Sunni-dominated kingdom, and marked the first time IS claimed an attack in Saudi Arabia.

"No, no, no... There is no action" in the form of retaliation, a Shiite resident who said he lost three friends in the Kudeih village blast told AFP.

"They just want justice."

Naseema Assada, a resident of Shiite-majority Qatif city near the stricken village, said she visited seven families affected by the attack.

"They are angry at Daesh and radical Sunnis," but not at Sunnis in general, she said, using an Arabic acronym for Daesh.

Residents said two children were among the dead, and plans were being made for a mass burial.

Demonstrators took to the streets of the eastern region on Saturday to denounce the attack.

In neighbouring Bahrain, Shiites marched in solidarity with the Saudi victims and clashed with riot police.

The mosque bombing occurred despite security checkpoints in Qatif, residents said.

"This is strange," Assada said. "The government should protect people and if it's not, this is the government's fault."

Such emotions are natural after a deadly incident but police have foiled many plots and have themselves become the most frequent targets of "terrorist" attacks, Interior Ministry spokesman General Mansour al-Turki told reporters on Sunday.

"We did not have any information or evidence that they were about to carry out a terrorist attack in any mosque anywhere in the kingdom," Turki said.

In a statement carried by the official Saudi Press Agency (SPA) late Saturday, the interior ministry identified the bomber as Salih bin Abdulrahman Salih al-Ghishaami, a Saudi national.

"He was wanted by security services for belonging to a terrorist cell receiving directions from Daesh abroad," the ministry said.

The militant group had already claimed Friday's attack but identified the bomber as Abu Amer al-Najdi.

"The cell was discovered last month, and so far 26 of its members, all Saudi nationals, have been arrested," the interior ministry said, raising the number of wounded from 81 to 101.

- Innocent civilians -

Ministry officials alleged the cell leader is Abdel Malik, who recruited relatives and friends and taught them how to use weapons.

In a telegram to Crown Prince Mohammed bin Nayef, who is also the interior minister, King Salman pledged the perpetrators would be brought to justice.

"Anyone taking part, planning, supporting, cooperating or sympathising with this heinous crime will be held accountable," the king said in the message carried by SPA.

"We were... pained by the intensity of this terrorist crime that contradicts the values of Islam and humanity" and which targeted innocent civilians, he added.

It is the second mass killing of Shiites in the kingdom since late last year.

In November, gunmen killed seven Shiites in the Eastern Province town of Al-Dalwa.

There was no violent Shiite backlash against that attack, which authorities said was linked to Daesh.

Daesh, which considers Shiites heretics, has declared a "caliphate" in parts of Iraq and Syria it controls. The group has claimed numerous atrocities including the beheading of foreign hostages.

Saudi Arabia and its Sunni Gulf neighbours last year joined a US-led military coalition bombing Daesh in Syria, raising concerns about possible retaliation in the kingdom.

Since late March, Saudi Arabia has also led a coalition bombing Iran-backed Shiite rebels who seized large parts of Yemen and have sent deadly shell fire into Saudi Arabia.

The interior ministry said the mosque attack against "honourable citizens was carried out by tools controlled by foreign forces that aim to divide the unity of society and pull it into sectarian strife".

Saudi Arabia's top cleric, Grand Mufti Sheikh Abdul Aziz al-Sheikh, called it a "criminal act" which targeted national unity.

But columnist Khaled Almaeena, writing in Sunday's Saudi Gazette, complained that "some imams spewed hatred and spread falsehood about Muslims of other sects.... we should not have remained silent".

Most of the kingdom's Shiites live in the east, where the vast majority of the kingdom's oil reserves lie but where Shiites have long complained of marginalisation.
Source: AFP