Israel says it has launched air strikes against Hamas targets in the Gaza Strip, after incendiary balloons were launched from the territory.
Explosions were heard in Gaza City in the early hours of Wednesday.
A BBC report states that Israel says several balloons, designed to cause fires, were sent from Gaza into Israel earlier on Tuesday.
It is the first major flare-up since a ceasefire on 21 May ended 11 days of fighting.
In a statement, the Israel Defense Forces (IDF) said its fighter jets had hit military compounds operated by Hamas in Khan Yunis and Gaza City.
It said “terrorist activity” took place in the compound, and that the IDF was “prepared for all scenarios, including the resumption of hostilities, in the face of continued terror acts from the Gaza Strip.”
No Gazans have been injured in the airstrikes, according to Hamas-affiliated media.
Israel’s fire service said the incendiary balloons launched from Gaza had caused at least 20 fires in fields by communities in southern Israel.
Hamas earlier threatened to take action over an Israeli nationalist march on Tuesday through occupied east Jerusalem.
Ahead of the march, local media reported that the Israeli military was on heightened alert. It also said Iron Dome missile defence batteries had been deployed to counter possible Palestinian rocket fire.