Palestinian artillery fire has wounded four Israeli settlers in the Gaza Strip.

The Palestinian group Hamas claimed responsibility for the attack near a Jewish settlement.

The group has been firing rockets and shells into the area since Friday.

Israel has threatened to launch an offense into the Gaza Strip if the attack does not stop.

Deputy Defense Minister Zeev Boim told Israeli radio that forces will enter the area within hours if Palestinian President Mahmoud Abbas fails to stop the militants.

Seperately, Israeli border police have killed a Hamas militant near another Gaza settlement.