Explosives were found planted at a memorial in Srebrenica (search), site of the worst massacre of the Yugoslav wars, before tens of thousands of people were expected to gather there for the 10th anniversary of the slaughter, police said Tuesday.

Radovan Pejic, spokesman for the Bosnian Serb police, said that police were informed of the explosives by the European Union peace force in Bosnia (search). Police sealed off the location Tuesday and sent bomb disposal experts and bomb-sniffing dogs to the memorial center, which is located in the Srebrenica suburb of Potocari.

"We found a significant amount of explosives at two separate locations and we have sealed off the wider region of Potocari," Pejic said.

"We have identified a few suspects and are searching for them now," he added.

Police officials at the site said 66 pounds of plastic explosive had been found.

Toward the end of Bosnia's 1992-95 war, as many as 8,000 Bosnian Muslim men and boys were killed when Bosnian Serb troops overran the eastern Bosnian enclave of Srebrenica in July 1995. It was Europe's worst mass killing since World War II.

The U.N. tribunal in The Hague, Netherlands, has called the Srebrenica massacre an act of genocide.

The 10th anniversary is scheduled for July 11 and organizers expect up to 50,000 people to attend, including regional leaders and international dignitaries.

Also, some 570 victims of the massacre, between the ages of 14 and 75, will be buried at the memorial cemetery during the ceremony. Their bodies were exhumed from more than 60 mass graves that have been found around this eastern Bosnian town.

More than 1,300 Srebrenica victims are already buried in the Potocari memorial cemetery. The masterminds of the massacre, Bosnian Serb wartime leader Radovan Karadzic (search) and his top general, Ratko Mladic (search) are still at large. Both have been indicted by the war crimes tribunal for genocide and crimes against humanity.

Srebrenica has again been the focus of public attention since early June, when footage of Serbian paramilitary forces killing six Srebrenica men was broadcast at the U.N. war crimes tribunal in The Hague.

Pejic said that some 1,500 police officers will be involved in securing the July 11 ceremony.