Israel's military said Monday its fighter planes struck Hamas facilities in the Gaza Strip after Palestinians fired rockets at the Jewish state.

Two rockets were fired from the Gaza Strip towards the coast near the southern city of Ashdod, according to a military statement.

"In response...fighter jets struck military targets belonging to the Hamas terror organisation in the Gaza Strip, including tunnel digging sites," the army said.

There were no reports of any damage from Palestinian rockets, with Israeli army sources indicating they had landed in the Mediterranean sea.

Palestinian security sources in Gaza said the Israeli fire hit "farmland" in the southern Khan Yunis area of the enclave, causing damage but no injuries.

There was no immediate claim for the rocket launches from Hamas-ruled Gaza.

Palestinians in Gaza and the Israeli-occupied West Bank are heading for respective legislative and presidential elections in May and July, the first in 15 years.

The polls are part of a warming of ties between Hamas and Palestinian president Mahmud Abbas's West Bank-based Fatah party.

The dates were announced on Friday in a presidential decree by Abbas.

In the last Palestinian parliamentary elections in 2006, Hamas won an unexpected landslide.

The polls resulted in a brief unity government but it soon collapsed. In 2007, bloody clashes erupted between the two principal Palestinian factions, with Hamas ultimately seizing control of Gaza.

Last week an Israeli tank fired at "a Hamas military post" in the southern Gaza Strip, after shots were fired at a military vehicle working on its side of the border fence, the Israeli army said.

In late December Hamas and Islamic Jihad staged joint military exercises in the coastal territory, during which they fired rockets out to sea, in the first exercise of its kind.

The Palestinian forces also simulated various combat scenarios with Israeli troops, an AFP reporter said.

The events marked the anniversary of the first Hamas war with Israel, in 2008, a year after the Islamists took power in Gaza.

Since then they have fought two more wars, in 2012 and 2014.