No Palestinians were injured during the bombardment, but severe damage was reported on some buildings. Israel says it's retaliating for kite, balloon and rocket attacks. The UN recently condemned Israel for using excessive force against Palestinians.
Israeli warplanes struck Hamas positions in Gaza early Wednesday after Palestinian militants there fired dozens of rockets and mortars at southern communities, the military said.
The Palestinian fire came hours after the Israeli military said it struck Hamas infrastructure in response to it called "arson balloons" launched from Gaza into Israel.
The military says it targeted 25 Hamas positions. Palestinian media released what they said were footage of the strikes.
No Palestinians were reported injured during the bombardment, but severe damage was reported on some buildings.
Gaza-based Palestinian media said that in retaliation to the earlier Israeli bombardment, Hamas fired 45 rockets into Israeli settlements near the Gaza border.
No injuries were reported and Israel said seven of the rockets were intercepted by its Iron Dome anti-missile system, while three landed within Gaza.
Tensions are high along the Gaza border after months of weekly rallies by Palestinian protesters, demanding their right to return to their homes in what is Israel today
Israel says it is defending a sovereign border and nearby communities and accuses Hamas of using the protests as cover for attempts to breach the border fence and carry out attacks.
Israel said the first round of strikes overnight were in retaliation to the launching of kites and balloons armed with crude incendiary devices into Israeli territory on Tuesday.
The makeshift devices sparked forest and brush fires in 15 locations in Israeli settlements, according to the government.
The UN General Assembly last week voted in favour of a resolution put forward by Turkey, Algeria and Palestine which condemned Israel for its "excessive use of force" against Palestinians.
The vote followed the killing of more than 120 Palestinians in recent months near the Gaza border as part of the ongoing Palestinian protests demanding the right to return. Israeli snipers have been targeting protesters who approach the border fence.
More than 10,000 others have been wounded in the rolling demonstrations which began in late March.