It is a crime too great to hide, but do we have the stomach to bring th e killers to trial?

Emma Daly entered the killing fields of Bosnia yesterday. At a mass grave near Zvornik, she found a vain attempt to cover up the slaughter

War crimes investigators yesterday began the search for evidence to support charges of genocide against Bosnian Serb leaders, amid signs that at least one mass grave has been violated recently in order to cover up evidence.

Despite the best efforts of those who would bury a crime too great to hide, the evidence of mass murder is there. It remains only to be seen whether the international community has the stomach to bring the murderers to trial.

A large section of earth has been freshly turned at one site suspected of housing the remains of more than 600 Muslim men who were executed after the fall of the town of Srebrenica in eastern Bosnia in July. The rest of the ground at the site, known as Sahinici One, shows old vehicle tracks and earthen mounds covered with young grass.

Nato's peace implementation force, I-For, has refused to secure the areas suspected of housing mass graves, saying it is not a military task. I- For officials said they had no evidence of tampering at any site, despite reporters' accounts of interference at more than one alleged grave. Yesterday, spokesmen refused to discuss the issue.

David Rohde, the only journalist known to have visited Sahinici One, shortly after the alleged killings, said yesterday that the remains he saw in the area last year, including clothing, spectacles, shoes and walking sticks, had been removed. "Seventy per cent of the larger grave has been dug up, and half of the smaller one," Mr Rohde said. "All of the jackets have gone, and all of the canes."

A six-man team from the International Criminal Tribunal on the former Yugoslavia has begun to survey the sites in search of evidence to support witnesses' reports and surveillance photos, which suggest Bosnian Serbs massacred at least 3,000 Muslims from Srebrenica and buried in them in at least 11 mass graves.

General Ratko Mladic and Radovan Karadzic, the Bosnian Serb leaders, have been indicted by the tribunal for genocide and crimes against humanity over the disappearance from Srebrenica of several thousand Muslims. At least 8,000 people from the enclave have been registered as missing.

Jean-Rene Ruez, leader of the tribunal team, refused to give details of the group's activities. But the team will start by surveying and marking the sites. It is not expected to exhume bodies for the time being., as experts say digging up bodies is of little use unless investigators have a list of potential names and detailed descriptions to match the remains.

US troops will provide "area security" for the tribunal, said Colonel John Batiste, the Nato commander in the area.

"They will not exhume remains. They will not investigate suspected atrocity sites.

"We will not guard sites, evidence or suspected war criminals. We will not be involved in witness protection."

Serb soldiers are suspected of tampering with graves elsewhere in Bosnia. But tribunal sources have said the testimony of witnesses and survivors, along with photographs, provides compelling evidence.

Opening the graves is vital to the families of those who are missing. Exhuming and identifying bodies is one of the few ways they will know whether their relatives are dead or alive.

Serb killing fields, page 10