The militants fired two missiles toward Israel's metropolitan area, both of which landed on open ground, the IDF said.
There have been no reports of fatalities, and it's unclear who did the launches.
The Israeli military said its Iron Dome air defense system has not defended the missiles despite previous reports to the contrary. He emphasized that his alerting and warning system had worked as needed.
About four hours after the launches, the IDF announced that it had begun in response to targets in Gaza. Reports from the area indicated that sites around Khan Younis in the south of the strip were among the first.
Militant factions in the Gaza Strip have denied the launch. [1
In a statement addressed to journalists, a spokesman for the Qassam Brigades pointed out that the launches had taken place during an attack by a security delegation from Egypt to Gaza, which led the mediation efforts between Israel and Hamas.
And a spokesman for the Islamic Jihad, a smaller militant group in Gaza, told CNN that he had denied the proposals to launch the rockets.
The launches come at a delicate moment.
Not Only Egypt is in the Middle Another attempt to achieve a long-term ceasefire between Israel and Hamas, but Israel is only weeks away from general elections.
Prime Minister Benjamin Netanyahu, who also serves as country's defense minister, met his military chiefs to decide on Israel's response.
Shortly after Israel began its retaliation, sirens sounding in another area just east of Gaza sounded like another rocket launch.
The IDF believed that a rocket had been fired from the Gaza Strip and failed to reach Israeli territory
Andrew Carey reported from Jerusalem and Ibrahim Dahman from Gaza.