A suicide attack on a Shia mosque in Saudi's Al-Qatif has raised the alarm about the cost of the kingdom's multi-front war as it backfires at home. Saleh Bin Abdul-Rahman Al-Qashaami, who blew himself up in the Shia mosque during Friday noon prayers, might be the Saudi answer to Mohamed Bouazizi, the Tunisian fruit vendor who set himself on fire, triggering the Arab Spring in 2011. Four years later, the violent chaos engulfing most of the region is also acquiring sectarian dimensions, which Al-Qashaami's 22 May suicide attack — killing 21 Saudi Shias and wounding 101 — seeks to ignite. According to the Saudi Interior Ministry, Al-Qashaami was wanted by security services for belonging to a terrorist cell and acted on orders from the Islamic State in Iraq and Syria (ISIS) terrorist group, which claimed responsibility for the attack. ISIS vowed dark days ahead for Shias until militants “chase them from the Arabian Peninsula”. Although Saudi officials condemned the bombing in the strongest words, state TV described the victims as “martyrs”, and Saudi Grand Mufti Sheikh Abdul-Aziz Al-Sheikh called the attack a “criminal act” that targeted national unity, the damage might be politically detrimental. Thousands turned up for the victims' funerals on Monday in the mainly Shia eastern province of Saudi Arabia, in a show of defiance against what they called “the Saudi aggression” on the Imam Ali Mosque where the bombing took place. Protesters carried placards naming Saudi clerics and ministries that directly or indirectly incite sectarian hatred against Shias, who are commonly referred to in the largely Sunni kingdom — the birthplace of Wahhabism, the ideological reference of ISIS — in derogatory terms. Shia slogans on the banners fluttered in the funeral-turned protest while the Saudi flag was conspicuously absent. Posters of jailed Saudi Shia cleric Nemr Baqer Al-Nemr, who was sentenced to death last year but not executed, dominated the march. Al-Nemr, who attacked the royal family, publicly supported the 2011 anti-government protests in the eastern province, which took their cue from the democracy movement in neighbouring Bahrain before it was quashed by authorities. Most of Saudi Arabia's Shia minority, who comprise 15 per cent of the population, live in the east province and complain of oppression and marginalisation. Although it is an oil-rich area, the east province's visible poverty is testament to its alienation. The 2011 “Saudi Spring” attempt was met with a zero-tolerance policy. Since then 20 protesters were killed by security forces. This is why the Saudi authorities' tolerance of the Monday funeral protest was noticeable. The Interior Ministry said the 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”. The bombing is the second deadly attack on Shias in Saudi Arabia since late last year when gunmen killed seven in Al-Dawla, the eastern province. At least 100 alleged militants with ISIS connections were arrested since. According to the Saudi Interior Ministry, the cell of the Friday suicide bomber was discovered last month and 26 of its members were arrested. They are all Saudi nationals and included two 15-year-olds and one other aged 16. The ministry said that five members confessed their involvement in the 8 May shooting of a policeman on patrol in southern Riyadh. The suicide attack raised concerns about the inevitable backfiring of Riyadh's regional role and recent multi-front war strategy against Iran, ISIS and Syrian President Bashar Al-Assad, in Yemen and Syria. The kingdom spearheaded a war on Yemen's Iran-backed Houthi rebels in March to remove them from power and reinstate exiled President Abd-Rabbu Mansour Hadi. But as the war enters its third month it has only plunged Yemen — already the poorest country in the Arab region — into a humanitarian crisis, displaced hundreds of thousands from their homes and together with the Houthi's counter attacks, killed over 1,000 and inadvertently empowered Al-Qaeda Yemen branch to expand in the south. The Saudi monarch's son and defence minister, Mohamed Bin Salman, is the war's mastermind. Riyadh is also part of the international coalition against ISIS, and together with Qatar and Turkey is actively supporting rebels in Syria against Al-Assad. But more significantly, the kingdom has deployed its regional and diplomatic leverage to counter what it calls Iran's growing influence while at the same time denying it is acting on sectarian motives. By posing as the region's strongman, Riyadh has become a primary target for its foes. But as Friday's suicide bombing demonstrates, it was ISIS, rather than Iran, that hit where it hurts most: its fragile sectarian balance. In an article published in Al-Raay Al-Youm, editor Abdel-Bari Atwan said that it took five months for Riyadh to engage in several war fronts — that is since King Salman succeeded his brother, the late King Abdullah. With the new monarch came a less than cautious Saudi doctrine that Atwan attributed to both the young defence minister and Crown Prince Mohamed Bin Nayef. The impulsive transformation of Saudi Arabia from its classic gradualism to a “confrontational” state in a matter of weeks, Atwan wrote, was met with more imprudence from the kingdom's religious and media institutions, which took sectarian incitement too far without thought of its dangers for Saudi Arabia in its domestic front. King Salman, Atwan added, wants Saudi Arabia to be seated as the Middle East's commander and to be anointed its leader by its military interventions in Yemen, Syria, Iraq, Bahrain and Libya. “But is this the time and is Saudi Arabia ready for that role?” Atwan asked.