A bomb blast has killed at least eight people, mostly children, at a middle school in the Iraqi capital Baghdad.

伊拉克首都巴格达一所中学发生炸弹爆炸事件，造成8人死亡，而且多数是儿童。

The explosion also wounded at least 40 others, reports say. The toll¹ is expected to rise.

The attack happened in the Shia neighbourhood of Sadr City, an impoverished贫穷的，赤贫的 area that is seen as a stronghold of Shia militants³.

Many children were returning to school for the first time after the Muslim feast of Eid al-Adha.

"Everything was thrown into the air. I went outside to see what had happened and saw children running in all directions四面八方," neighbour Umm Ali, who was injured in the blast, said.

It happened at 1310 local time (1010 GMT) at Abaa Dhar School for boys in the north-east of Baghdad.

Most of those killed and injured were children, police said.

Blood-soaked

The blast opened a gash裂纹，伤口 in a classroom wall, shattering windows and scattering⁵ desks.

Blood-soaked books were strewn around the school.

The explosion came after a rubbish tip inside the school was set fire to.

Iraqi security sources told reporters they believed a cache隐藏所 of explosives had been hidden by insurgents起义者，叛乱者 underneath⁷ the rubbish mound土墩.

Sadr City used to be one of the most violent neighbourhoods in Baghdad.

At the height of达最高点 the insurgency⁹ in 2006-2007 it saw some of the fiercest fighting, the BBC correspondent in Baghdad Natalia Antelava says.

There have been explosions at markets in Sadr City in recent months, but for residents the attack on children brings memories of some of the worst years of violence, our correspondent adds.

It comes a day after the Iraqi parliament passed the resolution paving a way for the general election in February.

The move was praised as an important step towards political stability but the explosion is a reminder¹⁰ of how unstable¹¹ and fragile security is.

Government figures show that violence in Iraq has fallen generally over the past 18 months.

There were 88 civilian¹² deaths last month, the lowest level since the 2003 US invasion.