At least 30 different sites in the Gaza Strip, belonging to Hamas and some militant groups, were hit by fire from Israeli tanks and aircrafts.
At least four Palestinians were injured when Israel fired missiles into the Gaza Strip on Sunday in retaliation to a rocket, allegedly fired from the Palestinian enclave, that crashed into the southern Israeli city of Sderot.
Israeli police said the rocket hit "between two buildings on a road" in Sderot, which is less than four kilometres from Gaza, causing no casualties.
A music festival in Sderot attended by hundreds of Israelis was temporarily disrupted as people sought shelter, television footage showed.
Israeli Army spokesman Peter Lerner said in a statement, "In response to the rocket attack from the Gaza Strip, the IAF (Israeli air force) and tanks targeted two Hamas posts in the northern Gaza Strip."
Palestinian health and security sources said two people were lightly wounded by the Israeli fire.
"One of them is a 20-year-old (young man) who was hit by shrapnel in the face," said Ashraf al-Qudra, spokesman for the Palestinian health ministry in Hamas-controlled Gaza.
Later on Sunday, two more Palestinians were wounded by further Israeli strikes in the area, Qudra added.
The Palestinian Information Centre quoted local sources as saying that Israeli artillery fire hit an agricultural land in al-Masriyyin neighborhood in Beit Hanoun damaging a water reservoir.
Two lesser known militant groups, one of them aligned with DAESH, claimed responsibility for the rocket attack on Sderot, according to Israeli media.
Hamas spokesman Sami Abu Zuhri said: "We hold (Israel) responsible for the escalation in the Gaza Strip and we stress that its aggression will not succeed in breaking the will of our people and dictate terms to the resistance."
Hamas controls the Gaza Strip and has observed a de-facto ceasefire with Israel since a 2014 war but some small militant cells have defied the agreement and have continued to occasionally launch rockets at Israel.
Israel has held Hamas responsible for all attacks originating in the coastal enclave.
More than 2,100 Palestinians, mostly civilians, were killed during the 2014 Gaza conflict. Sixty-seven Israeli soldiers and six civilians in Israel were killed by rockets and attacks by Hamas and other militant groups.
On July 2, Israeli air raids hit four sites in Gaza after a rocket struck a building in Sderot. There were no casualties in either incident.