Palestinian militants in Gaza fired two rockets toward the Mediterranean sea on Saturday, causing an explosion off the shore of Tel Aviv, Israel's military said.
Police said there were no casualties or damage.
There was no immediate claim of responsibility from Gaza militants for the rocket firing or comment from Hamas, the Islamist armed group that rules the coastal Palestinian enclave.
Hamas has occasionally test-fired rockets, launching them toward the sea.
The Hamas-affiliated Paltimes news website said, however, that the launch was not deliberate and was probably caused by a malfunction.
The Israel-Gaza frontier has been largely quiet since an 11-day war in May. But on Wednesday, gunfire from Gaza that wounded an Israeli civilian drew tank fire from the Israeli military, wounding three Palestinians.