Moussa told an emergency meeting of Arab League ambassadors that “the Arab bloc in the United Nations has been directed to ask for the convention of the Security Council to stop the Israeli aggression on Gaza and impose a no-fly zone.”
Israeli and Palestinian officials were on Sunday floating a ceasefire to end fighting in the coastal strip where Israeli air strikes have killed at least 18 people since Thursday.
But Israeli Prime Minister Benjamin Netanyahu has warned of an even stronger response if more rockets are fired from the Palestinian territory controlled by the Islamist movement Hamas.
The flare-up came after an anti-tank missile fired from Gaza hit an Israeli school bus on Thursday, wounding two people, one of them critically.
Even if Arab representatives at the United Nations succeed in convening a Security Council meeting, the US, a close ally of Israel, is likely to veto it.
The Arab League request for a no-fly zone over Gaza may have been inspired by a UN-sanctioned aerial blockade for Libya to halt forces loyal to Muammar Qadhafi harming civilians.
Arab League backing for that no-fly zone was seen as crucially important by the USs when it pressed for a UN resolution that authorised it and other countries to keep Libyan planes grounded.