BAGHDAD — First came the fireball, then the screams of the victims. The suicide bombing just outside a Baghdad graveyard knocked Nasser Waleed Ali over and peppered his back with shrapnel.
Ali was one of the lucky ones. At least 51 died in the Oct. 5 attack, many of them Shi’ite pilgrims walking by on their way to a shrine. No one has claimed responsibility, but there is little doubt Al Qaeda’s local franchise is to blame. Suicide bombers and car bombs are its calling cards, Shi’ite civilians among its favorite targets.
Al Qaeda has come roaring back in Iraq since US troops left in late 2011 and now looks stronger than it has in years.
The terror group has shown it is capable of carrying out mass-casualty attacks several times a month, driving the death toll in Iraq to the highest level in half a decade. It sees each attack as a way to cultivate an atmosphere of chaos that weakens the Shi’ite-led government’s authority. Al Qaeda’s extremist ideology considers Shi’ite Muslims to be heretics.
The wave of violence continued across Iraq on Sunday, when a string of bombings, many in Shi’ite-majority cities, killed at least 42 people and wounded dozens, officials said.
There was no immediate claim of responsibility for the latest attacks, but waves of bombings are frequently used by Al Qaeda.
The deadliest of Sunday’s attacks, many of which struck busy commercial areas, happened in the southern city of Hillah, 60 miles south of Baghdad. Back-to-back car bombings hit an outdoor market there, killing eight people and wounding 22, police said.
Two parked car bombs ripped through a commercial area in the city of Suwayrah, 25 miles south of Baghdad, killing five people and wounding 14. Two other car bombs exploded simultaneously in the city of Kut, 100 miles southeast of Baghdad, killing four and wounded 16, according to police.
Other bombings were reported Sunday in Samawah, Diwaniyah, and Samarra.
Recent prison breaks have bolstered Al Qaeda’s ranks, while feelings of Sunni marginalization and the chaos caused by the civil war in neighboring Syria are fueling its comeback.
‘‘Nobody is able to control this situation,’’ said Ali, who watches over a Sunni graveyard that sprang up next to the hallowed Abu Hanifa mosque in 2006, when sectarian fighting threatened to engulf Iraq in all-out civil war.
‘‘We are not safe in the coffee shops or mosques, not even in soccer fields,’’ he continued, rattling off some of the targets hit repeatedly in recent months.
The pace of the killing accelerated significantly following a deadly crackdown by security forces on a camp for Sunni protesters in the northern town of Hawija in April. United Nations figures show 712 people died violently in Iraq that month, at the time the most since 2008.
The monthly death toll has not been that low since. September saw 979 killed.
Al Qaeda has begun actively recruiting more young Iraqi men to take part in suicide missions after years of relying primarily on foreign volunteers, according to two intelligence officials. They said an order had been issued calling for 50 attacks per week, which if achieved would mark a significant escalation.