The United Nations refugee agency, UNHCR, said on Friday that Iraqis represent the largest national group of asylum-seekers around the world, although the numbers have fallen sharply since the overthrow of former ruler Saddam Hussein.

"The situation in Iraq remains volatile, with an absence of law and order in many parts of the country," spokesman Rupert Colville told journalists.

"We have advised states to continue a ban on forced returns to Iraq, including of rejected asylum-seekers," he said, adding that he was not aware of any attempt at forced repatriation.

The Geneva-based agency estimates there are around 500,000 Iraqis, one in six of the total number living abroad, who could be vulnerable to expulsion either because they have overstayed their visas or their requests for asylum have been rejected.