Hundreds of Iraqi Christians filled Our Lady of Salvation church in Baghdad amid tight security on Monday to mark the first anniversary of a massacre of worshippers and priests by militants.

The church's interior is still pock-marked by bullet holes, even a year after the attacks claimed by Al-Qaeda's local affiliate, the Islamic State of Iraq, that killed 44 worshippers, two priests and seven security forces members.

Robes of the two priests who were killed were hung inside the church.

And large pictures of those killed in the attack hung outside the church yard, along with posters with messages including "We condemn the killing of Iraqi Christians" and "Where is the international voice?"

Security was very tight at the church, with rifle-armed police on rooftops in the area and security forces searching people and their bags as they entered.

The attack, and violence in Iraq in general, has deeply affected worshippers at the church.

"I have to pray before I go to work. You can be killed here at any moment," said Nofal Sabah, a 30-year-old cook who was carrying a young child asleep on his shoulder.

Three of Sabah's brothers were inside the church when it was attacked, he said. One was wounded and was being treated in Lyon, France, while another "has psychological problems because he saw everything."

"My family is ready to sell all (our) property to buy something abroad," Sabah said, adding that there were difficulties with visas.

Some people pay $10,000 to be smuggled to Germany, he said. "I'm thinking of doing that too."

Bushara Georges, 50, also had relatives who were present during the attack.

"I have a lot of sadness... I was in Syria but my relatives were in the bathroom (just outside the church), hiding during the attack," Georges said.

"They had a child crying; the mother had to put her hand on his mouth. They were safe, but then they fled to Lebanon, they were scared," she said.

She said she would like to emigrate as well, but "it's a matter of money."

Louis Climis, a priest at the church who was wounded in the attack, said the government has not done enough for Iraqi Christians.

"One year after the massacre, you really feel that the government did not do anything... to find a solution to (Iraqi Christians') problems," Climis said.

"I am one of the victims," he said. "I was wounded, I was operated on in Italy."

But he added: "I have not thought of leaving my Iraq. This is my country... I am Iraqi before I am Christian."

Muslim clerics also gathered at the church, in a show of support for their fellow Iraqis.

Hundreds of thousands of Iraqi Christians have fled abroad to escape bloodshed here since the 2003 US-led invasion.