Amr al-Khafaji, a spokesman for the displacement and migration ministry, which oversees the refugee camp at Al-Qaim, told AFP that 150 people had crossed from Syria on Tuesday.

But unmarried male Syrians under the age of 50 remain barred from entering Iraq, Khafaji said, a policy apparently aimed at keeping out military-age men who may pose a security threat.

The crossing had been closed since August 15 for "security reasons," Khafaji said.

Rebels opposed to President Bashar al-Assad's regime took over the Syrian side of the crossing in July, although there has since been fighting between pro- and anti-regime forces near the border.

Iraqi officials said that Syrian warplanes passed briefly through Iraqi airspace on August 23 in a bombing run on the town of Albu Kamal, on the Syrian side of the border.

And on September 7, either mortar rounds or rockets fired from Syria hit Al-Qaim, killing a young Iraqi girl and wounding four other people, according to Iraqi officials.

The Syria Regional Refugee Response website of the UN High Commissioner for Refugees says there are 25,508 registered Syrian refugees in Iraq, of whom 4,521 are in Anbar province, where Al-Qaim is located.

A further 10,914 are awaiting registration, according to UNHCR.