Palestinian militants in the Gaza Strip fired a rocket at Israel late Monday, the army said, without reporting any casualties.
Sirens sounded in areas of southern Israel neighbouring Gaza to warn of the incoming fire, for which there was no claim of responsibility.
The last cross-border rocket attack, after which Israel retaliated with air raids, coincided with the September 15 signing in Washington of normalisation deals between the Jewish state and two Gulf countries.
A truce mediated by Qatar has since held.
Israel had previously bombed Gaza, ruled by the Islamist group Hamas, almost daily since August 6, in response to the launch of airborne incendiary devices and rocket fire.