Israeli warplanes struck suspected Hamas positions in the southern Gaza Strip after Palestinian militants fired dozens of rockets and mortars at southern communities early on Wednesday, the military said.

It was the biggest flare-up between the sides in weeks, but no casualties were reported in either Israel or Gaza.

Video posted on social media showed large explosions and smoke rising from the impact of Israeli airstrikes in Gaza.

Israel said it targeted about 25 suspected Hamas targets in response to the heavy Palestinian fire.

Hamas praised the militant attacks, but did not take responsibility for them.

The Israeli military said Palestinians fired about 45 rockets and mortars at Israel.

Seven projectiles were intercepted by the Iron Dome defence system and at least three fell prematurely, landing inside Gaza, it said.

Some rockets exploded inside Israel, damaging property.