BEIRUT, Lebanon — The missiles struck after dark, hitting facilities in Syria where Iran and its militant proxies had set up camp, setting buildings on fire and causing an explosion so large that it shook the ground like a minor earthquake.

But neither the presumed attacker, Israel, nor the reported victims, Iran and its allies, said much as the dust settled on Monday. Both sought to manage the escalation in the battle between them that has been building for years in the shadows of the war in Syria.

The strikes hit a munitions storage site on Sunday, destroying a cache of missiles and killing at least 16 people, many of them Iranians, according to a conflict monitoring group and one of Iran’s regional allies. Other reports suggested higher death tolls.

Much more was at stake, however, as Iran and its foes in the region — Israel, Saudi Arabia and the United Arab Emirates — compete for power in the Middle East while trying to subvert their enemies’ plans.