Israeli aircraft bombed two targets in the northern Gaza Strip Monday, following the launch of several missiles and mortar shells into Israel by Palestinian militants, dpa reported.
Security officials of the radical Islamist Hamas movement ruling Gaza and witnesses said that a training ground of Hamas' armed wing, the Qassam Brigades, was struck north of Gaza City.
Ashraf al-Qedra, the spokesman of Gaza's emergency services, said there were no injuries.
Palestinians said it was the first Israeli airstrike in Gaza in about a year.
An Israeli military statement said the targets hit were two concealed rocket launchers.
Earlier, Gaza militants launched two missiles at the southern Israeli coastal city of Ashkelon early Monday.
An Israeli army spokeswoman in Tel Aviv said a battery of Israel's Iron Dome short-range missile defence system shot down one missile over Ashkelon. Another probably fell in an open area outside the city. Security forces were searching for it.
On Sunday, Palestinian militants also launched a mortar shell from the southern Gaza Strip, which fell near the security fence on the border, on the Israeli side.
The violence comes hours after Israel said it would release another 26 Palestinian prisoners this week, possibly Tuesday night or Wednesday morning.
A forum of senior Israeli ministers headed by Prime Minister Benjamin Netanyahu authorized the list of 26 names Sunday, after which the Israel Prison Service (IPS) published the list on its website at midnight (2200 GMT Sunday). The release will take place at least 48 hours later, Netanyahu's office said in a statement.