A mass grave of Jews murdered in the Holocaust has been sold by a Ukrainian city to a residential building developer who is planning to establish real estate projects on the site.

Some 5,000 Jews were shot dead in the city of Poltava in eastern Ukraine after the Nazis reached the location in September 1941. They, along with many non-Jews who were also murdered, were buried in a mass grave.

Now, the municipality is planning real estate development on the site, despite protests from the local Jewish community and the Ukrainian Institute of National Remembrance.

Israeli Ambassador to Ukraine Joel Lion issued a letter to Poltava Mayor Oleksandr Shamota urging him to cancel the plan.

“As a representative of the State of Israel, the state of the Jewish people, and as a son of Holocaust survivors, I speak on behalf of those who cannot speak anymore and appeal to your conscience and to the members of your city council to stop this historic injustice,” Lion wrote. “I expect immediate action. You can choose between justice and injustice.”

Copies of the letter were also sent to Ukrainian Prime Minister Volodymyr Groysman, Culture Minister Yevhen Nyshchuk and multiple Jewish community leaders.

Jews comprised almost 10 percent of the Poltava population when the Nazis arrived in the city (which is currently home to 300,000 people) and constituted an important center of Jewish life. Many of the nearly 13,000 Jews living there escaped prior to the occupation.

Second president of Israel Yitzhak Ben-Zvi was born in the city, and the Hamodia and Hapeles Haredi newspapers were established there.

Last year, “The Grieving Mother” monument for Holocaust victims in Poltava was vandalized with “Heil Hitler” and “Death to the Kikes” spray-painted on it.