By Dan Williams and Angus McDowall JERUSALEM/BEIRUT (Reuters) – Israel said it attacked nearly all of Iran’s military infrastructure in Syria on Thursday after Iranian forces fired rockets at Israeli-held territory for the first time. It was the heaviest Israeli barrage in Syria since the start in 2011 of its civil war, in which Iranians, allied Shi’ite militias and Russian soldiers have deployed in support of President Bashar al-Assad. A war monitor, the Britain-based Syrian Observatory for Human Rights, said the Israeli strikes killed at least 23 military personnel, including Syrians and non-Syrians.