By Kareem Raheem
BAGHDAD (Reuters) - Bombings and shootings targeting Shi'ite Muslim pilgrims in Baghdad and police across Iraq killed at least 53 people on Wednesday in apparently coordinated attacks during a major religious festival.
Violence in Iraq has eased since the height of the war, but Islamist insurgents tied to al Qaeda are still potent, often targeting Shi'ite pilgrims to try to reignite the sectarian tensions that drove Iraq close to civil war in 2006-2007.
In Wednesday's attacks, at least 18 people were killed when four bombs hit pilgrims across Baghdad as they gathered to mark the anniversary of the death of Shi'ite imam Moussa al-Kadhim, a great-grandson of Prophet Mohammad.
One of those blasts killed at least nine people as pilgrims passed through a police checkpoint in central Baghdad.
"A group of pilgrims were walking and passed by a tent offering food and drinks when suddenly a car exploded near them," said Wathiq Muhana, a policeman whose patrol was stationed near the blast in Karrada district.
"People were running away covered with blood and bodies were scattered on the ground," he said.
Extra security and checkpoints have been in place this week as thousands of pilgrims arrive in Baghdad to meet at a shrine in the capital's northern Kadhimiyah district for the Shi'ite religious festival.
In a separate attack on Wednesday in the mainly Shi'ite southern city of Hilla, police said two car bombs, including one detonated by a suicide bomber, exploded outside restaurants used by security forces, killing 22 people and wounding 38.
"When a minibus packed with policemen stopped near the restaurants, a car exploded near the bus," said Maitham Sahib, owner of a restaurant in Hilla near the blast. "It's heart breaking. It is just sirens, and screams of wounded people."
Two more car bombs killed four people in the Shi'ite city of Balad, a car bomb in Kerbala killed 3 and wounded 17, and another car bomb in Haswa, 50 km (30 miles) south of Baghdad, killed one person, and wounded four.
Five soldiers were also killed by gunmen in an attack on an army checkpoint in the south of the capital, police said.
Wednesday's attacks came at a sensitive time.
On Sunday, at least six people were killed and 38 wounded when two mortar bombs struck a square packed with Shi'ite Muslim pilgrims in Baghdad's Kadhimiyah district.
Earlier this month, 26 people were killed and more than 190 wounded when a suicide bomber detonated an explosive-rigged car outside a Shi'ite religious office in the capital.
Al Qaeda's Iraqi affiliate, Islamic State of Iraq, claimed responsibility for the attack on the religious office.
Political tensions have been high in Iraq since the last American troops left in December, with the fragile government - split among Sunni-backed, Shi'ite and ethnic Kurdish blocs - feuding over their power-sharing accord.
Shi'ite Prime Minister Nuri al-Maliki is fending off attempts by Sunni, Kurdish and some Shi'ite rivals to organize a vote of no confidence against him. Critics accuse him of trying to consolidate his position and failing to fulfill promises to share power among the blocs.
(Additional reporting by Ahmed Rasheed in Baghdad; Writing by Patrick Markey; Editing by Janet Lawrence)