The Gaza Strip's rulers Hamas fired rockets into the sea on Monday after repeated exchanges of fire with Israel in recent days, Palestinian security sources and eyewitnesses said.
At least eight rockets were seen in the sky, heading toward the Mediterranean Sea, said AFP journalists in the coastal strip, which has been under Israeli blockade for more than a decade.
The interior ministry of the Palestinian enclave under Hamas control since 2007 referred to "an act of resistance".
The rockets were a "message" to Israel to let it know that armed groups in Gaza will not "remain silent" in the face of an Israeli blockade and "aggression", a source close to Hamas told AFP.
The source noted that Monday's rocket fire coincided with the recent launch of incendiary balloons into Israel.
In the past week, such balloons have flown three times from Gaza into Israel, each time triggering retaliatory strikes against Hamas positions.
The latest came Sunday night when the Israeli military announced that one of its aircraft had struck at a Hamas observation post in northern Gaza.