This aerial view shows the power station and industrial zone of Ashkelon, Israel, in March of 2008.
The missile fired from a Grad rocket launcher did not cause any injuries or damage in the coastal city, said a spokesman for the Israel Defense Forces.
Rockets fired from a Grad have a longer range than the crude, home-made Qassams that Palestinian militants in Gaza fire more frequently. Militants have used Grads to strike farther into Israel.
Ashkelon lies 12 miles (19 km) north of Gaza.
Israel and Hamas, the Islamic militant group that has ruled Gaza since 2007, declared separate, tentative cease-fires two weeks ago after more than three weeks of fighting in Gaza.