Egypt said on Monday it formally requested that Israel look into a statement attributed to Foreign Minister Avigdor Lieberman in which he described Egypt as more "worrying" than Israel's arch-enemesis Iran.

A foreign ministry statement said Foreign Minister Mohammed Kamel Amr asked Cairo's ambassador in Tel Aviv to request "clarifications on the accuracy of the statement attributed to the Israeli foreign minister."

The Israeli daily Maariv had quoted Lieberman as saying: "The Egyptian issue is far more disturbing than the Iranian question."

Egypt's relations with Israel have worsened since an uprising ousted president Hosni Mubarak, seen as a friend of the Jewish state, in February 2011.

Egypt announced on Sunday that it had annulled a contract to export gas to Israel, accusing it of failing to meet its financial obligations under the deal.

Israel has expressed concerns over rocket attacks against its cities from Egypt's Sinai Peninsula, home to Islamist and Bedouin militants who have repeatedly bombed the pipeline supplying gas to Israel.