Having fled a city where shells fell "like rain" and children died in front of them, Syrian refugees spoke of the hell that would erupt every night as troops sought to retake their border town.

Wearing a dirt-covered dishdasha, or traditional Arab robe, his face pale from exhaustion, Ahmed Saleh Hanoush sat on the floor of a school-turned-dormitory for refugees, fighting back tears.

"My son was hit by a shell when he was in our garden speaking on the phone," the 53-year-old said of the 17-year-old who suffered chest, arm and leg wounds from the Syrian army's bombardment aimed at winning back control of Albu Kamal, a town on the Iraq-Syria border held by rebels.

"I took him to an emergency clinic," Hanoush said, his hands placed on the heads of two of his daughters, "but there was nothing there to clean his wounds."

Pausing for a moment, the father of five said: "He died in front of my eyes. I tried, but I could not do anything for him."

Hanoush is one of around 750 Syrians who crossed the border from Albu Kamal into Al-Qaim in Iraq after the Baghdad government had a change of heart and decided to allow in refugees from its strife-hit neighbour.

The Syrian border town has been short of food and medicine for the past two months, as government forces and rebel troops battled.

Opposition forces finally took Albu Kamal last week, and it is now the only one of three main border crossings between Iraq and Syria that is in rebel hands.

The Syrian army has been shelling it heavily on a near-nightly basis, and a medic in Albu Kamal who spoke to AFP by telephone said the onslaught had killed nearly 30 people in the past week.

Dr Anas Fadhel at Al-Qaim hospital said the facility had also treated 10 Syrians wounded in the shelling.

"I lived in terror for three weeks after my husband Ahmed left for Damascus to get medical supplies," refugee Maysam Umm Khalid, a 35-year-old mother-of-three, told AFP.

"He never came back, and his phone has been off since then.

"I did not know what to do during the night. The night was for the bombs, which were hitting the city like rain. It was a hell that would erupt for several hours, before calming down and then erupting again."

An official in Al-Qaim said around 750 Syrians had crossed the 600-kilometre (375-mile) border between the two countries after Baghdad announced on Tuesday it would set up refugee camps.

Speaking on condition of anonymity, the official said 250 held dual Iraqi-Syrian nationality, and most were women.

Iraq initially resisted accepting refugees from the conflict, saying it would only allow Iraqis fleeing the violence to cross the frontier, but reversed its decision on Monday and has since allocated $42 million to build camps for refugees.

It has also set up a committee headed by the immigration minister and including representatives of the interior, defence and transport ministries, as well as the Iraqi Red Crescent and the two border provinces of Anbar and Nineveh.

Until the camps are ready, however, the interim arrangements are spartan.

Three schools in Al-Qaim have been converted into makeshift refugee camps.

At the school housing Hanoush and his family, refugees' belongings are strewn all over the courtyard as they wait in the boiling Iraqi summer.

The police and army search everything entering or leaving the school, and have set up a security checkpoint, barring Syrians from leaving and only allowing their Iraqi relatives to visit.

Many Sunni tribes have long lived in the area where the border now lies, so residents of Al-Qaim have relatives from blood and marriage living in Albu Kamal.

"We escaped the sectarian violence in Homs," said Abdul Nasser Abu Jamal, referring to the central Syrian city, "and we went to Albu Kamal because it is far from all the other cities."

"But when the city was being shelled and we heard the decision from the Iraqi government that it would let us in, we decided to come."

He surveyed his surroundings grimly: "I wish we had not come -- this is a place for rubbish, not for people to live."

Another former Homs native who passed through Albu Kamal, a 25-year-old who declined to be identified, said of his new residence: "We were in a big prison (in Albu Kamal), and now we are in a small prison."

"There we could die in a few minutes if we were hit by a shell, but here it seems we will die slowly."