Thousands of people have been gathering at a field near the Bosnian town of Srebrenica for a ceremony marking the largest single atrocity in the Bosnian war.

Men and boys were taken away and executed, including my parents and my brother.

Hasan Nuhanovic, survivor

About 7,000 Muslim men were killed by Bosnian Serb forces as they attempted to flee the town in July 1995.

There were emotional scenes as relatives of the dead gathered at the field in the village of Potocari.

The commemoration comes amid renewed tension in the Serbian part of Bosnia - where Srebrenica is located.

Tight security

The BBC's Matthew Price in Potocari says women wearing traditional dresses and headscarves handed flowers to each other.

Many wiped the tears from their eyes and some fainted

A symbolic headstone is to be unveiled in the field. The site is due to be turned into a burial ground for the victims later this year.

Memories are only too fresh

Tight security is in place: Around 2,000 members of the local police force are on duty. Road blocks have been set up across the area.

The commemoration is held every year, but our correspondent says there is more potential for tension this year.

In recent days two Serbs indicted for war crimes - Miroslav Deronjic, 47, and Radovan Stankovic, 33 - have been arrested and sent to the international criminal tribunal in The Hague.

Since last year's commemoration, Bosnian Serb General Radislav Krstic has been convicted of genocide for his role in the Srebrenica massacre - he received a 46-year prison sentence in August 2001.

But the top Bosnian Serb genocide suspects - former President Radovan Karadzic and army chief Ratko Mladic - remain at large.

Both have been indicted in connection with the Srebrenica massacre and other atrocities committed during the Bosnian war.

Sanctuary

Since last year, fresh details have also emerged about the international community's failure to protect the civilians of Srebrenica.

Srebrenica update

July 2002: Suspects transferred to The Hague April 2002: Dutch cabinet resigns following report August 2001: General Krstic sentenced

The town had been designated a safe area by the United Nations, which had troops stationed there.

But when Serb forces advanced in July 1995 the lightly-armed Dutch peacekeepers were unable to stop them.

In April, an official Dutch report on the massacre blamed the country's government, military officials and the United Nations for failing to prevent the atrocity.

The Dutch cabinet and the head of the country's army resigned as a result.

"The Dutch battalion soldiers and officers ordered all the refugees who were inside their base to leave the base," Hasan Nuhanovic, a survivor who was then an interpreter for the UN, remembers.

Thousands of bodies are stored in Tuzla

"All the 6,000 refugees were handed over to the Serb troops and all the men and boys among these people were taken away and executed, including my parents and my brother," he says.

"I couldn't believe it was happening to my family."

The bodies of many of those killed at Srebrenica - perhaps around 4,000 - remain in storage in the nearby town of Tuzla, where the process of formally identifying the dead continues.