Updated at 1:35 P.M. E.S.T.

JERUSALEM — After Northern Israel was put on alert by reports of hostile aircraft entering from Lebanon, Israel’s military walked back the claim as a possible false alarm.

The Israeli military had said Wednesday night that aircraft crossed over from Lebanon, setting sirens blaring across northern Israel as it urged citizens there to shelter.

Authorities are reportedly investigating if the alarm was caused by a system error or a possible cyber attack.

The apparent incursion from Lebanon came amid efforts by Israel to form a unity government at Jerusalem and air strikes in response to the Hamas attack are hitting Gaza.

The military did not specify the kind of aircraft. But Lebanon’s Iranian-backed Hezbollah and Palestinian militants are known to have drones and gliders.

Israeli sources tell the Sun that a siren was heard as far as Israel’s third largest city, Haifa.

The news came after Hezbollah fired anti-tank missiles at an Israeli military position earlier Wednesday, claiming to have killed and wounded troops.

The Israeli army shelled the area in southern Lebanon where the attack was launched.