Many of the dead in the Iraqi capital were Shia pilgrims gathering for a religious festival., the BBC informs. In Hilla, two car bombs exploded near a restaurant, killing at least 21 people.There has been a wave of attacks on the Shia community in recent days, as it marks the anniversary of the death of Shia imam Moussa al-Kadhim. The first car bomb struck a procession of pilgrims in the town of Taji, north of Baghdad, as they made their way to a shrine. There was then a series of four further blasts across the capital. A man who witnessed one of the attacks in Baghdad said a car bomb had targeted pilgrims and had also hit people who were working in the city.“People were slaughtered and killed right here. This wrecked car here belonged to a man who worked to earn his living, and another one belonged to a fuel seller. They could not find his body.” Another man, speaking from his hospital bed in Baghdad, explained what happened. “A car bomb exploded suddenly. I fell on the ground, then so many people fell on me.”The restaurant that came under attack in Hilla is said to be frequented by police. Pictures from the scene showed the mangled remains of a restaurant, damaged cars and roads strewn with debris. Three bombs exploded in Kirkuk, with one of them targeting the headquarters of Kurdish President Massoud Barzani. One person died and many were injured in that attack.Violence in Iraq has fallen since the sectarian killings of a few years ago, but militants still frequently attack security forces and civilians.Wednesday has been one of the deadliest days of violence since US troops withdrew from Iraq last December. It is not yet clear who is responsible. Sectarian tensions have been simmering since the US withdrawal, and this kind of violence is exactly what they had feared. Shia Prime Minister Nouri Maliki has been trying to consolidate Shia power at the expense of Sunni and Kurdish voices, she says. Mr Maliki is currently pursuing an arrest warrant for the Sunni Vice President, Tariq al-Hashemi. He is accused of funding attacks on government and security officials during Iraq’s bloody insurgency.