FROMELLES, France (AFP) - Forensic experts gathered Monday in a muddy field in northern France ahead of a solemn operation to exhume hundreds of fallen Australian and British soldiers from a World War I mass grave. On Tuesday, the team will start recovering the bodies of up to 400 servicemen from a patch of land just outside Fromelles, a cluster of red brick homes and tidy flower gardens near what was once the frontline. Genetic testing will hopefully allow some of the men to be identified to their surviving relatives and all will finally be granted the honour of a full military funeral, more than nine decades after they fell. Weve had some very emotional moments. Pilgrims have been in tears, Peter Francis, spokesman for the Commonwealth War Graves Commission, told AFP at the site, a day before it is sealed off for the six-month excavation. We know we are going to come face to face with the human cost of the Great War. The Australians and Britons, lost in the Battle of Fromelles on July 19, 1916, are thought to have been buried in pits by German forces, without their nametags, in a location known as Pheasants Wood. The forces ranged against them included the regiment of a young Austrian corporal called Adolf Hitler, though historians are not sure he took part in the battle. Since the site was identified in 2007, thanks to the work of an Australian amateur historian, hundreds of pilgrims, most of them Australian, have visited this quiet corner of rural France. From July next year they will be greeted by a new Commonwealth war cemetery where each unknown soldier will have been reburied with his own headstone and full military honours. Test digs on the site revealed buttons from Commonwealth military underwear, and in 2008 human remains turned up in five separate pits at the site, perhaps the largest unmarked war grave found since the 1918 Armistice. Today a 30-strong international team-including forensic anthropologists and scientists with expertise ranging from Roman archaeological digs to the Srebrenica war crimes investigation in Bosnia-is on site. An ordnance officer is also on hand in case they come upon any of the unexploded munitions which still turn up every year in the fields of northern France, scene of fierce fighting in World Wars I and II. Our goal is to give these soldiers a burial fitting of the sacrifices they made, said Louise Loe, project manager at British firm Oxford Archaeology, which is running the dig on behalf of the Commonwealth commission. Working in crime-scene conditions, with protective body gear and face masks, experts will take DNA samples from the teeth and bones of a dozen soldiers in coming weeks to find out if it is still viable. To identify the fallen men, they hope to compare their genetic profiles with living relatives, and cross-reference it with military and family records, and clues such as facial features or signs of childhood illness. It is a giant puzzle-in fact I dont think anyone has worked on a puzzle on this scale before, said Peter Jones, the Commonwealth genetics specialist. Britain has drawn up a list of 350 soldiers it believes may be buried at Fromelles, while Australia has 191 names, partly based on information volunteered by the public. British and Australian troops were ordered to attack on the evening of July 19, 1916, advancing in clear view of the enemy, who fired on them as if they were sitting ducks. Some 5,553 Australian and 1,547 British soldiers were killed, the worst loss of life for the Australian Imperial Force in a 24-hour period, more even than on the worst day of the fighting in Gallipoli in 1915.