The Israeli military said early Friday it has begun attacking sites in the Gaza Strip in response to a rocket attack on Tel Aviv.
Palestinian resistance group Hamas denied involvement for the rocket salvo, which it said took place as its leaders met Egyptian delegates about efforts to secure a long-term ceasefire with Israel.
The attacks were taking place in the southern Gaza town of Khan Younis, about 25 kilometers (15 miles) south of Gaza City.
The warplanes could be heard flying overhead in Gaza City, where smoke from the explosions could be seen in the distance.
In a statement early Friday, the army said it was targeting "terror sites." It gave no further details.
Palestinian media said a naval base of Hamas had been targeted.
There were no immediate reports of injuries.