Israeli aircraft struck militant targets in the Hamas-controlled Gaza Strip early Thursday after a rocket from the coastal territory landed in southern Israel, the Israeli military said.
A passerby was lightly hurt in the Gaza Strip, according to residents.
No damage or injuries were reported in Israel after warning sirens sounded and the rocket struck open ground near the city of Ashkelon before dawn, the army said.
Rocket launchings have become an almost weekly occurrence from the coastal strip recently but no militant group took immediate responsibility for the attack.
"The repeated rocket fire at Israel ... is a deliberate decision to target civilians. No person should live under the threat of terrorism," Israeli military spokesman Lieutenant-Colonel Peter Lerner said in a statement.
A group that sympathizes with al-Qaida, who have defied Hamas, has been blamed for other recent strikes, none of which caused injuries or damage.
The Israel-Gaza border area had largely been quiet since last year's July-August war, when Palestinian militants launched thousands of rockets and mortar bombs into Israel and Israeli shelling and airstrikes battered the enclave.
More than 2,100 Palestinians were killed, most of them civilians, while 67 soldiers and six civilians were killed on the Israeli side.