Some survivors were too distraught to take part in the march

The Bosnian Muslims began the journey from the Crni Vrh mass grave where 600 bodies were exhumed last year.

They were retracing their steps - skirting minefields - back to the city where about 8,000 Muslim men were killed by Serbs in July 1995.

It was the worst atrocity in Europe since World War II.

Bosnian Serb forces carried out the killings after overrunning the eastern Bosnian town, which the UN had declared a "safe area".

We were an easy target and many got killed in ambushes, or crossing the roads or when they shelled us in the woods Dzevad Malkic Survivor

Ten years on, the men wanted by the United Nations war crimes tribunal at The Hague - Bosnian Serb leader Radovan Karadzic and his military commander, General Ratko Mladic - are still at large.

This has cast a shadow over the 11 July commemorations, correspondents say.

On Monday, explosives were found at the Srebrenica memorial centre.

Awareness

About 500 Muslim survivors began the three-day 73km (45 mile) march on Friday, watched by Bosnian Serb police and helicopters hovering above. Some were too distraught to take part.

"We will try to avoid paths through woods that could still be mined. The last thing we want to see is that someone gets hurt on this route again," said Ramo Dautbasic, 37, the organiser of the memorial march.

Experts began excavating a new mass grave in Srebrenica on Friday

"We were ambushed several times. The Serbs killed without prejudice, everyone - young or old, man or boy," Mr Dautbasic told the Associated Press news agency.

Mr Dautbasic took seven days to escape - but Dzevad Malkic took 27.

"We were an easy target and many got killed in ambushes, or crossing the roads or when they shelled us in the woods," Mr Malkic, 46, said, quoted by Reuters news agency.

"I waited for 15 days to cross a road in the village of Kamenica. But when I saw how many people got killed trying it I turned around and headed west," he said.

A video released at the trial of former Serb leader Slobodan Milosevic in May showed a group of Muslim teenagers being killed at Srebrenica in 1995.

The footage showed six teenage boys, their hands bound, being led from a truck and shot.