Palestinians fired four rockets into southern Israel on Tuesday, the third day of a fragile truce declared by Gaza militants, the military told AFP. \"Two were shot down (by Israel\'s Iron Dome air defence system) and another two fell on open ground,\" an army spokesman said. \"As far as we know there were no injuries or damage,\" police spokesman Micky Rosenfeld added. Nine rockets have been fired at Israel since the Hamas rulers of the Gaza Strip declared a truce effective from midnight Saturday, the military said. Prime Minister Benjamin Netanyahu said on Sunday that Israeli troops had responded \"forcefully\" to recent rocket fire from Gaza and could step up their response if the latest truce failed to hold. \"Regarding the situation in the south, the Israeli army acted forcefully against those who try to attack us and, if necessary, the army will act more forcefully still,\" Netanyahu warned at the start of a cabinet meeting. A previous truce, announced last Wednesday, had begun to unravel, with Hamas threatening to call it off altogether before declaring a fresh attempt.