The Popular Front for the Liberation of Palestine
(PFLP) fired several rockets into Israeli communities near the Gaza Strip Sunday.
The PFLP, the largest faction in the Palestine Liberation Organization (PLO) after Fatah,said in a statement that its militants fired "tens of rockets" at Israel.
But Israeli army radio reported that two missiles landed at western Negev on Sunday,causing no damage or casualties.
On Saturday, a PFLP leader addressed tens of thousands of supporters in Gaza, who rallied to mark the 42nd anniversary of its establishment that his movement has not agreed to halt attacks against Israel.
Earlier, an official from the Islamic Hamas movement which controls Gaza said an agreement had been reached with all factions to suspend firing rockets at Israel to avoid a possible Israeli military reaction.
Israel launched a three-week offensive in Gaza at the beginning of this year, during which 1,387 Palestinians were killed and thousands of houses were destroyed.
Israel said the war was aimed to stop Gaza militant groups, mainly Hamas, from firing rockets at Israeli towns.