Jerusalem ( CNN ) -- Israeli authorities discovered and disarmed an explosive barrel Wednesday , the third to wash up on an Israeli beach this week , the Israel Defense Forces said . The barrel was found Wednesday afternoon at Palmachim beach south of Tel Aviv . On Monday , Islamic Jihad , the Fatah Al Aqsa Martyrs Brigade and the Nasser Salah A din Brigades issued a leaflet in Gaza claiming responsibility for sending three explosive devices to the coastal cities Ashkelon and Ashdod . The other two barrels packed with explosives -- one found at Ashkelon and one at Ashdod -- were discovered Monday and disposed of . In response , the IDF said , the Israeli Air Force attacked `` two Hamas terrorist targets '' in southern Gaza . `` One of the targets was a terror tunnel , used for the infiltration of terrorists into Israel , while the other was used for smuggling of weapons . Direct hits were identified , '' the IDF said . Hamas , the movement controlling Gaza , has been vowing retaliation against Israel since one of the founding members of its military wing , Mahmoud al-Mabhouh , died last week in Dubai . Al-Mabhouh 's brother , Fayek al-Mabhouh , said that preliminary results of Hamas ' investigation of the death showed his brother was killed by electrocution and strangulation with a piece of cloth . Hamas officials accused Israel of assassinating Mahmoud al-Mabhouh . Israeli officials have not responded to that allegation .
Various Islamic groups issue a leaflet in Gaza claiming responsibility for sending devices . In response , the IDF said , the Israeli Air Force attacked `` two Hamas terrorist targets '' in southern Gaza . Hamas vowing retaliation against Israel since one of founding members of its military wing died last week in Dubai .