He said Islamic Jihad was behind the mortars but that Israel held Hamas responsible for any attacks emanating from Gaza.
Israeli forces have maintained regular incursions into the Gaza Strip along both the land and seaside borders. It proved to be a false alarm.
"In response to the mortar shells fired at a military post adjacent to the northern Gaza Strip, (Israeli) tanks and (Israeli) aircraft targeted four Hamas military posts in the northern Gaza Strip", the army said in a statement. Service resumed about two hours later.
Daud Shehab, the leader of Islamic Jihad in Gaza, said the "Zionist aggression" was an attempt to distract from the killing of a Palestinian man in the West Bank by settlers earlier in the day. The IDF claims it is retaliation for a mortar shelling of an Israeli outpost by another militant group.
The attack apparently set off rocket sirens in the Israeli town of Sderot and other communities surrounding the Gaza Strip. That attack killed at least 14 terrorists, including two of the organization's top commanders.
Israel and Hamas, the militant Islamist group that controls the Gaza Strip, have fought three wars since 2008. Occasional exchanges of fire continue to occur along the border.