Earlier, Gaza militants on Thursday fired an anti-tank missile at an Israeli school bus, critically injuring a teenager.

After the missile slammed into the bus, the Palestinians lobbed at least 45 mortar rounds into southern Israel, hitting a house, and the army responded by staging multiple raids across the enclave, one of which hit an ambulance, Palestinian medics said.

As the rockets flew over the border, Israel’s Iron Dome short-range missile defense system intercepted a projectile heading for the southern port city of Ashkelon, in what was the first time the system has ever been successfully used in a combat situation, according to AFP. The bus attack was the first time an anti-tank missile had hit a civilian target in Israel, prompting Israeli Defense Minister Ehud Barak to order the army “to act swiftly” in response.

In Al-Qarara village southern the Gaza Strip, Israeli helicopters opened heavy gunfire toward agricultural lands. In a similar attack, a Palestinian boy was wounded in eastern Khan Younis city. According to witnesses and medical sources, the boy was playing nearby his house when the Israeli tanks and helicopters targeted the area.

Two people were wounded in an Israeli shelling to the areas nearby the Gaza international air sport southeast of Rafah city.

The violence, part of the ongoing tit-for-tat along the Israel-Gaza border, comes hours after Israeli warplanes bombed four tunnels, three of them under the Gaza-Egypt border used for smuggling. One Palestinian worker was slightly injured Thursday when the Israeli bombed the tunnel he works in at the southern Gaza Strip borders with Egypt.

Also on Thursday, Israeli fighter jets attacked an open area near Gaza City and farmland near the central borders with Israel. No injured people were reported in these two attacks.

On Wednesday, four Palestinian civilians including a pregnant woman were wounded as Israeli warplanes bombarded a number of targets northern and eastern parts of the Gaza Strip.