An explosive device detonated along Israel's border fence with Syria on Tuesday afternoon, the IDF said, in the area south of the Druze village of Majdal Shams. Four IDF soldiers were wounded in the blast, one is in serious condition, the others are in light to moderate condition. The IDF has reportedly responded with artillery fire into Syrian-controlled territory, targeting Syrian military positions. According to the IDF, it fired Tamuz missiles and direct hits were confirmed. The condition remains serious of the IDF soldier wounded in the roadside explosion along the northern border in the Golan Heights on Tuesday. The director of Haifa's Rambam hospital said the soldier has undergone two head surgeries and is under anesthesia. Three other soldiers were lightly wounded when an explosive device detonated near their patrol. The Israel Air Force hit targets in southern Syria after the attack. Prime Minister Binyamin Netanyahu and Defense Minister Moshe Yaalon on Wednesday visited the soldiers and their families in hospital. Deputy Defense Minister Danny Danon says Israel is closely following developments in Syria and Lebanon, and will not allow a deterioration in the security situation in the north. Speaking on Reshet Bet, Danon said that Israel demands that the Syrian regime and Lebanese government ensure quiet along the border. He stressed that Israel will respond to any fire on its soldiers, to the detonation of explosives devices, or a kidnap attempt. Syria has lodged complaints with the United Nations secretary general and the chairman of the Security Council over artillery fire by the IDF and IAF aistrikes in Quneitra -- which were in retaliation for the security incident in the Golan Heights. The two letters called the Israeli action a flagrant breach of ceasefire accords.