VUKOVAR, Croatia (Reuters) - Excavators dug through piles of waste at a garbage dump surrounded by sunflower fields in Croatia on Thursday, searching for bodies of victims killed in war more than three decades ago, after remains of 10 people were found earlier this month.

The mss grave was located after two years of active searching at the Petrovacka Dola dump near Vukovar. Investigators expect to find more remains, said Ivona Paltrinieri, who heads the department for missing people in the war veterans ministry.

Croatia is still trying to establish the fate of 1,797 missing people from its 1991-1995 war of independence from then-Yugoslavia, including 500 people missing from Vukovar-Srijem county, Paltrinieri said.

Investigators believe the victims found this month at the dump had been reburied there after initially being buried elsewhere, as they were covered with earth and sludge that is not typical for the site.

Paltrinieri said the remains were probably moved to the dump in January 1992, after the temporary occupation of Vukovar which was reduced to rubble by the Yugoslav army and Serb paramilitary units in a three-month siege in late 1991.

"In all these decades of search, this Petrovacka Dola location is the largest, the most extensive and most complex," she said. "Until now, we have not had such a dump, where we dug 14 metres deep and excavated over 90,000 cubic meters of waste."

"It's like looking for a needle in a haystack, to comb through the piles of garbage to find the mortal remains - I think it's incredible."

The next step is the identification of the remains based on DNA analysis, matching the DNA with those of about 10,000 people who seek their missing relatives.

A total of 150 mass graves and a large number of individual graves have been found in Croatia since the war.

According to the International Commission for Missing Persons (ICMP), 11,600 people are still unaccounted for from the Balkan conflicts in the 1990s which broke out as Yugoslavia disintegrated into separate entities. Most are in Bosnia and Herzegovina.

(Reporting by Antonio Bronic, writing by Daria Sito-Sucic; Editing by Peter Graff)

By Antonio Bronic