Germany on Wednesday urged its citizens to leave Lebanon quickly as it warned of a potential war with Israel after a drone strike in Beirut killed a senior leader of the Palestinian terrorist group Hamas.

"All German citizens, who are still in Lebanon, are asked to register on the ELEFAND crisis preparedness list and to leave the country as quickly as possible," wrote the German foreign ministry on X.

The warning came after a meeting Wednesday of the German government's crisis unit.

"A further deterioration of the situation and expansion of the conflict cannot be ruled out, especially given the killing of Saleh al-Aruri," the political number two of Hamas in Beirut on Tuesday, the ministry wrote.

"This applies above all to the southern part of Lebanon, up to and including the southern urban areas of Beirut."

Although Israel has made no claim, Hamas, Hezbollah and Lebanese security sources blamed it for the assassination of al-Aruri, 57, one of the founders of Hamas' military wing. 

Lebanon's Iran-backed armed group Hezbollah has vowed to retaliate against Israel for the drone strike in its Shiite Muslim stronghold of southern Beirut.

Germany had already issued a warning against travel to Lebanon in October, in the wake of the outbreak of the Israel-Hamas war.