A senior Islamic Hamas movement official in Gaza on Monday called on United Nations Secretary General Ban Ki-moon to quit his post "because of his full partiality towards Israel."

Mahmoud Zahar, who served as a foreign minister in the former Hamas-led government, accused Ban of violating the rules of the international organization "by his biased attitudes towards Israel."

"We follow up with a great concern the biased steps carried out by the UN in relation to Middle East conflicts," Zahar said in a written statement.

Hamas, which is listed as a terrorist organization by the European Union and the U.S., took control of the Gaza Strip by force when its militants unseated Palestinian Authority Mahmoud Abbas' Fatah security forces in mid- June.

"The UN biased stance towards Israel contradicts with the basic role of the organization to restore security and settlement and achieve justice in the world," al-Zahar said.

Zahar also referred to Special rapporteur on human rights in the Palestinian territory John Dugard, who has accused Israel of committing crimes against the Palestinians in the West Bank and Gaza.

"There is an increasing partiality towards the Israeli occupation, and not only this, but also it [the UN] adopts the occupation's position. It also goes far beyond this and justified the occupation's crimes," Zahar said.