The air raids on Monday followed a barrage of rocket fire from the Strip into Israel earlier in the day.
Israel said its Iron Dome system intercepted many of the more than 100 missiles fired from the Palestinians. One, however, hit a bus and another struck a building in southern Israel.
Along with the air raids, Israeli artillery units also shelled positions across the enclave.
The rising tensions came as thousands of people took part in rallies in the Hamas-administered enclave following the killing of seven Palestinians - including Nour Baraka, a prominent commander of the al-Qassam Brigades, the armed wing of Hamas - in the secret Israeli military raid on Sunday evening.
One Israeli lieutenant colonel was also killed and another one was seriously injured in the attack.
Hamas leader Ismail Haniya led a funeral for Palestinians killed on Sunday as mourners called for revenge. Later, Palestinian factions said in a joint statement that they had begun firing rockets into Israel in response to the Israeli military incursion.
"Over the past two hours, the Israelis have targeted many resistance training camp and many buildings," Mukhaimar Abusada, professor at Gaza's al-Azhar University, told Al Jazeera on Monday evening. "It seems to me that we are going to witness a very hard night as a result of the ongoing Israeli retaliation."