Swadi said 20 people were wounded when the blasts wrecked classroom windows, spraying glass and injuring a number of the pupils.
"Anybody can be targeted"
Hoda Abdel-Hamid, Al Jazeera's correspondent in Baghdad, said: "The five schoolgirls died today because these mortars were lobbed randomly at the neighbourhood ... If you speak to Iraqis they will tell you anybody can be targeted everyday."
"Bush's strategy has failed totally in Iraq"
Dimos, Hania-Crete, Greece
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Earlier an explosive device hidden in a bag and left by a passenger on a bus, detonated in the Baladiyat area in eastern Baghdad, killing at least one passenger and wounding five others, police said.
Also on Sunday, eight people were killed and 18 wounded in a midday car bombing in Baghdad's Sadr City, a predominantly Shia area, according to a security source.
A Shia official at the Iraqi industry was also killed in a drive-by shooting along with his daughter.
Reports said the official's car was attacked by armed men who killed him, his driver and his 27-year-old daughter.
Abdel-Hamid said: "Attacks on officials are very common in Iraq - they are usually accused of being collaborators."
Last Wednesday, Iraq's higher education minister, a Sunni, escaped an assassination attempt. Armed men opened fire on his motorcade as he was traveling in southern Baghdad, killing one of his guards and wounding another.
Later a bomb hidden in a bag exploded in an outdoor market in the Baiyaa neighbourhood in western Baghdad, an area that is mostly Shia, although a significant number of Sunni Muslims also live there.
At least two people were killed and 17 wounded, including two children, police said.
Iraqi police detonated a bomb in Tayaran Square after evacuating the busy commercial area. No casualties were reported.
In the northern Iraqi oil city of Kirkuk two car bombs killed 16 people and wounded at least 30 on Sunday, Torhan Yussef, a police commander, said.
The first explosion was in front of a car showroom in the city's northern Almaz district, a normally peaceful area inhabited largely by Kurds and Christians.
Yussef said: "Eight people were killed and 18 wounded in the attack."
A second car bomb killed eight people and wounded 12, he added.
The US military reported its troops captured 21 "suspected terrorists" in a series of raids in Baghdad and areas north and west of the capital on Sunday.
A US commander said three of the suspects were believed to have close ties to the leadership of al-Qaeda in Iraq.
About 50,000 Iraqi police and soldiers and 35,000 US troops are being deployed under a new security plan across Baghdad, where more than 16,800 civilians were killed last year, according to the UN.