BAGHDAD, Oct. 6 (Xinhua) -- Suicide bomb attack targeting Shiite pilgrims in northern and central Iraq on Sunday killed 27 people and wounded 147, amid growing sectarian tension that threatens to bring the country to all-out sectarian strife.
In northern Iraq, up to 15 people were killed and some 122 others wounded when two suicide car bombs went off at a village near the city of Tal Afar in Iraq's northern province of Nineveh, Abdul- Aal al-Abbasi, an official in Tal Afar local government told Xinhua.
"The reports said that a total of five policemen, school principal and nine school children were killed and 122 people were wounded in the two suicide car bombs near a school and a police station in the village of Qabat," Abbasi said.
Most of the wounded were school children and many of them are in critical condition, Abbasi added.
One of the blasts occurred when a suicide bomber blew up a truck loaded with explosives near a primary school in a predominantly Shiite Turkoman village outside the city of Tal Afar, about 430 km north of the Iraqi capital of Baghdad, Abbasi said.
The explosion damaged part of the school building. The Iraqi security forces and rescue teams rushed to the scenes to remove the debris of building in search for victims, Abbasi added.
Another car bomb went off near a police station in the same area, Abbasi said without giving further details.
Ambulances, police and civilian vehicles are evacuating the victims to medical centers in nearby Tal Afar city, he added.
The predominantly Sunni Nineveh province and its capital Mosul, some 400 km north of Baghdad, has long been a stronghold for insurgent groups, including al-Qaida militants, since the U.S.-led invasion of Iraq in 2003.
Separately, another suicide bombing occurred on Sunday afternoon when suicide bomber blew up his explosive vest among a crowd of Shiite pilgrims in Seliekh district in the northern part of Baghdad, killing 12 people and wounding 25.
The attacks came as thousands of Shiite pilgrims walk from Baghdad districts in processions to commemorate the death of Imam Mohammed al-Jawad, the ninth of the 12 most revered Shiite Imams, whose tomb located in the center of the old part of the holy Shiite Kadhimiya district.
The attacks also came one day after a wave of massive bombings across Iraq, including a deadly suicide bombing targeting Shiite pilgrims in Baghdad that killed at least 78 people and wounded some 166 others.
No group has so far claimed responsibility for the attacks, but the al-Qaida front in Iraq, in most cases, were responsible for such massive attacks, raising fears that the terrorist group and other militia could return to widespread violence, particularly as Iraq is trying to fend off the spillover of the escalating violence in neighboring Syria.
The sectarian tension has been growing since late December 2012, when the Sunni Muslims started their protests against the Shiite- led government in six of Iraq's predominantly Sunni provinces and the Sunni districts in Baghdad.
The Sunnis accuse the government of marginalizing them, and claim that the Shiite-dominated Iraqi security forces were indiscriminately arresting and torturing their sons.
However, the worst security deterioration in Iraq began on April 23 after the security forces cracked down on a Sunni Arab protest camp in the northern city of Hawijah. The crackdown sparked fierce clashes across the country's predominantly Sunni provinces between the Sunni tribes and the security forces.
Iraq is witnessing its worst eruption of violence in recent years, which raises fears that the country is sliding back to the full-blown civil conflict that peaked in 2006 and 2007, when monthly death toll sometimes exceeded 3,000.
The UN Assistance Mission for Iraq said that almost 6,000 civilians were killed and over 14,000 others injured in Iraq from January to September this year.