The Israeli air force raided the northern Gaza Strip on Monday, just hours after militants there fired rockets at the self-prolciamed Jewish state, witnesses and the army said.
It was the first air strike on Gaza in more than two months and took place as Israel pushed forward with plans to release a new batch of veteran Palestinian prisoners.
Palestinian witnesses said the attack targeted a training ground used by militants from the armed wing of Gaza's ruling Hamas movement west of Beit Lahiya, but no-one was hurt.
The military confirmed the air force had struck Gaza following rocket fire on southern Israel.
"In response to rocket fire at Israel, the IDF (military) targeted 2 rocket launchers in Gaza. Direct hits confirmed," the army said on its official Twitter feed.
An earlier army statement said two rockets were fired towards the port city of Ashkelon, one of which was shot down by Israel's Iron Dome Missile Defence System. No damage or injuries were reported.
It was the first air strike since August 14 when the air force hit targets in the same area also in response to rocket fire, in a development which took place just hours after Israel released a first batch of Palestinian prisoners.
The skies above Gaza have been calm for months, although militants fired a mortar shell on Sunday.
During September, there were two instances of rocket fire, but Israel did not respond.
Late on Sunday, Israel approved the release of 26 veteran prisoners who will be freed on Tuesday.
It will be the second such release of Palestinian prisoners under terms of the US-backed direct peace talks which began in late July after a hiatus of nearly three years.
All but one of them were arrested before the signing of the 1993 Oslo Accords, with 21 from the West Bank and the rest from Gaza.