French President Emmanuel Macron held phone calls with top political and military leaders from Lebanon, his office said on Thursday, urging restraint after a wave of explosions of pagers and radio devices.
Macron asked Lebanese leaders to pass on messages to local groups including Hezbollah to avoid further escalation, the Elysee said, amid fears of a wider war.
Thousands of explosions in booby-trapped radios and pagers hit the Iran-backed group on Tuesday and Wednesday.
The attacks on Hezbollah's communications equipment killed 37 people and wounded around 3,000, raising fears that a full-blown war was imminent.
Israel has neither confirmed nor denied being behind the attacks, but multiple security sources have said they were carried out by its spy agency Mossad.
Spain's foreign ministry condemned the attacks as a violation of international humanitarian law that threatened the region's stability.
"We call for restraint on the part of all actors," the ministry said in a statement. "It's necessary to avoid a further escalation of violence and the risk of open war with unforeseeable consequences."
Spain's condemnation came hours after Palestinian Authority President Mahmoud Abbas met with Prime Minister Pedro Sanchez in Madrid.