Paris  - US and Polish troops participating in the 2003 invasion of Iraq to topple Saddam Hussein caused severe and irreparable damage to the ruins of the ancient city of Babylon, UNESCO said Thursday in Paris.

"The soldiers probably tore out stones while they were seeking souvenirs," the British Museum's John Curtis, a specialist in Mesopotamian and Persian antiquities, told journalists.

A group of international researchers said in a report prepared for UNESCO that, in 2003 and 2004, the occupation groups actually removed hills from the site that contained parts of the ancient city that had not yet been unearthed.

Dragon figures decorating the fabled Ishtar Gate, part of the walls of Babylon, were also damaged by soldiers in search of souvenirs, Curtis said.

From April 2003 to December 2004, the residence of the legendary King Nebuchadnezzar II (about 630-562 BC) was surrounded by a military base for coalition forces that was originally to have been used to protect the site from thieves and vandals.

According to the report, substantial damage was caused to the archaeological city by "digging, cutting, scraping and levelling."

The report noted that there were no signs of "malicious or accidental damage" to the city since December 2004.

"The major problems now arise from neglect and lack of maintenance," the report says.

Babylon is located 90 kilometers south of Baghdad. The entire site comprises an area of 9.56 square kilometers. It has been listed as an archaeological site since 1935. Although partially excavated over the last century, much of ancient Babylon still remains to be discovered.(dpa)