Cairo: When Khalid Al Harbiya arrived at the Neurosurgery Teaching Hospital in Baghdad, none of the doctors had informed him his 12-year-old daughter Zynab had died.

He saw her lifeless body sprawled in the morgue after she was killed in a bombing by Islamic State terrorists who simultaneously attacked other parts of Iraq killing at least 35 and injuring more than 100 people.

"I started banging on my head… when I saw. It was so traumatic" he told Fairfax Media the day after burying her.

"May God avenge us from Daesh," he said using the pejorative term used commonly in Arabic for IS.

The Sunni hardline group has ramped up its attacks in recent days throughout the region as Muslims enter the first week of fasting for the holy month of Ramadan.

IS has been losing its territorial stronghold in Mosul, Iraq's second largest city, to Iraqi forces and Shiite paramilitary groups forcing it to intensify its suicide bombings targeting mostly Shia Iraqis.

Australian-born Zynab was visiting her family, especially her ailing grandfather, in Iraq for the fourth time during her short life.

She had been sitting in the back of a car in the sweltering Baghdad heat on the way to grab an ice cream to break her Ramadan fast along with her mother, two younger brothers, aunt and grandmother in the upmarket Karrada district teeming with cafes and shoppers, according to Mr Harbiya.

A car packed with explosives struck just after midnight near al-Faqma, a popular ice cream shop.

Mr Harbiya's family, including his sister in law who sustained minor injuries, all survived except Zynab. Thirteen others were killed alongside her.

"It was such a brutal death. She was just a little girl, what has she ever done to anyone? She was not in the army or a fighter. They are criminals, they have no mercy, no humanity – they are monsters", he distressingly added on the line from Baghdad.

Videos posted on social media show carnage, billowing smoke and bodies littered across the bustling shopping area.

The labourer from Thomastown in Victoria who has lived in Australia for 20 years after he escaped the dictatorial reign of ousted autocrat Saddam Hussein, heard about the attack on Facebook. He hurriedly drove from al-Nasiriya, about five hours south of Baghdad, knowing that he might not see his family again.

"I was praying incessantly on the way saying 'God please make sure they are fine'."

He had spoken briefly to Zynab a day before she was killed.

"She would always ring to check on me. She asked me if she can go buy the new iPhone 7 and I told her 'OK darling'. It was so quick".

He said she was a caring and helpful youngster.

"Normally your child survives you, not the other way around.

"From the day she was born until she died, she never gave me any trouble. She never cried… When we would go shopping, I would tell her 'what would you like?' and she would say 'whatever you want'. She had strong convictions and was creative."

Sirius College, Zynab's school in Melbourne, posted a message paying tribute to her and noting the local community was "deeply saddened".

Foreign Minister Julie Bishop condemned the attack and said the family is being provided with consular assistance, which Mr Harbiya confirmed and appreciated.

"We are heartened by the support from Australia. We are Muslims being targeted and these terrorists know no difference. We must stand together to fight against Daesh and terrorism."

Mr Harbiya's wife Habayeb has gone into shock over losing her daughter. His sons Haydar, 10, and Bilal, 7, are traumatised.

"They wanted to see their sister but we stopped them because the scene is too horrific," he told Fairfax Media while holding back tears. "They are crying all the time saying 'we want our sister back'."

IS militants hit the same district of Karrada in July 2016 with a truck bomb that killed at least 324 people, making it the deadliest attack in Iraq since the US led invasion of the country in March 2003.

He described a chaotic hospital with bodies being wheeled in and out by doctors and nurses amid anguished cries from families trying to determine if their children were killed.

Mr Harbiya is unsure when he will return to Australia given a period of mourning for his daughter.

"She wanted to be a lawyer or a teacher or a doctor. She wanted to help people, I swear." he said. "She had a big heart."