KIEV, Ukraine (AP) — A mass grave holding the remains of thousands of Jews killed by the Nazis has been found in southern Ukraine near the site of what was once a concentration camp, a Jewish community representative said Tuesday.

The grave was found by chance last month when workers were preparing to lay gas pipelines in the village of Gvozdavka-1, near Odessa, said Roman Shvartsman, a spokesman for the regional Jewish community.

The Nazis established two ghettos during World War II near the village and brought Jews there from what is now Moldova as well as Ukrainian regions, Shvartsman said. In November 1941, they set up a concentration camp and killed about 5,000 Jews, he said.

"Several thousand Jews executed by the Nazis lie there," Shvartsman told The Associated Press.

Efraim Zuroff, director of the Israel office of the Simon Wiesenthal Center, said the finding was no surprise: "It underscores the enormous scope of the plans of annihilation of the Nazis and their collaborators in eastern Europe."

"The scope is enormous, the number of places where murders were carried out is very large and that is why even now at this point, so late after the events, graves are still being discovered," he added.

Yitzhak Arad, a Holocaust scholar and a former director of the Yad Vashem Holocaust Museum, said his research indicated some 28,000 Jews were gathered in the area from surrounding towns. He said 10,000 of those died at a rate of around 500 people a day.

Shvartsman said that Jewish community knew about the mass killing but did not know where the bodies were located.

Anatoly Podolsky, director of the Ukrainian Center for Holocaust Studies, said there are believed to be some 250-350 mass grave sites from the Nazi occupation, during which some 1.5 million Ukrainian Jews are believed to have been killed — including those massacred near their homes and those deported to camps elsewhere. He said most of the site have been discovered, many of them since the Soviet collapse of 1991, but others have not.

"Ukraine was an enormous killing field, hundreds of thousands of Jews were murdered and the entire region is literally filled with hundreds of mass graves," Zuroff said.

Ilia Levitas, the head of Ukraine's Jewish Council, put the number of mass Jewish graves in the country at over 700 and said more than 100 are without monuments to the victims.

According to Shvartsman, the names of 93 Jews killed at the Gvozsdavka-1 site have been established. He said Jewish community members plan to conduct studies at the site to identify more victims.

"We must figure out their names. It is our debt before victims and survivors," he said.

Odessa's chief rabbi, Shlomo Baksht, hopes to fence the site off and erect a monument to the victims by the end of the year.

Ukraine's Jewish population was devastated during the Holocaust. Babi Yar, a ravine outside the capital Kiev where the Nazis slaughtered some 34,000 Jews over two days in September 1941, is a powerful symbol of the tragedy.

About 240,000 Jews were killed by the Nazis in the Odessa region, according to Shvartsman. He said a mass grave with remains of about 3,500 Jews was found in the region last year.