Hamas condemned the United Nations on Sunday, saying it planned to teach Palestinian children in the Gaza Strip about the Holocaust – but the UN agency which runs schools in the enclave would not confirm any change.

Branding the Nazi genocide of the Jews "a lie invented by the Zionists", the Islamist movement which runs the Gaza Strip wrote in an open letter to a senior UN official that he should withdraw plans for a new history book in UN schools.

A spokesman for the United Nations Relief and Works Agency (UNRWA), which educates some 200,000 refugee children in Gaza, said the Holocaust was not on its current curriculum. He would not comment on Hamas's statement that it was about to change.

Palestinians resent the way world powers reacted to the Holocaust by supporting the establishment of Israel in 1948, a move that left half the Arab population of then British-ruled Palestine as refugees in Gaza, the West Bank and abroad.

Hamas said it believed UNRWA was about to start using a text for 13-year-olds that included a chapter on the Holocaust.

In an open letter to local UNRWA chief John Ging, the movement's Popular Committees for Refugees said: "We refuse to let our children study a lie invented by the Zionists."

UNRWA spokesman Adnan Abu Hasna said: "There is no mention of the Holocaust in the current syllabus." Asked if UNRWA planned to change that, he declined to comment.

In the West Bank, run by the Western-backed Palestinian Authority of President Mahmoud Abbas, teachers said there was no official guidance on teaching about the Holocaust.

Israelis are angered by denial of the Holocaust among some in the Middle East, notably lately by leaders in Iran, who provide support for Hamas. Abbas, who has engaged in negotiation with Israel, has had to distance himself from his own 1980s doctoral thesis, which cast doubt on the scale of the Holocaust.

Hamas' official spokesman in Gaza, Sami Abu Zuhri, said he did not want to discuss the history of the Holocaust but said: "Regardless of the controversy, we oppose forcing the issue of the so-called Holocaust onto the syllabus, because it aims to reinforce acceptance of the occupation of Palestinian land."