"During the day, arson balloons were identified as having been launched from the Gaza Strip into Israeli territory," the army said in a statement.

"In response, an IDF (Israeli Defence Forces) aircraft targeted a Hamas military post in the southern Gaza Strip," it added.

A Palestinian security source in the Hamas-ruled coastal enclave said an Israeli aircraft fired three projectiles at an observation post and farmland east of the Bureij refugee camp in Gaza, causing damage but no casualties.

The Israeli strike is the first on Gaza since January.

Israel and the Islamist movement Hamas have fought three devastating wars since 2008.

Tensions have risen again since March as Palestinians have gathered along the border with Israel for often violent protests, calling for an end to the blockade.

At least 250 Palestinians have since been killed by Israeli fire, the majority shot during clashes, though others have been hit by tank fire or air strikes.

Two Israeli soldiers have been killed over the same period.