The Syrian military reported the attack, saying it had left two people dead near the town of Masyaf in western Syria and had caused unspecified material damage.
Israeli officials did not comment on the strike, but a Syrian monitoring group and a former Israeli official said it had targeted a research site that produced chemical weapons.
Israel has repeatedly hit targets in Syria during the country’s six-year civil war, most of them thought to be weapons convoys belonging to Hezbollah, the Lebanese militant group that is one of Israel’s fiercest enemies.
The strike reported on Thursday came a day after a United Nations commission accused the Syrian government of using chemical weapons in an attack in April that killed dozens in the village of Khan Sheikhoun and flooded clinics with victims gasping for breath.
The unequivocal condemnation from the United Nations undercut claims by Syria and its ally, Russia, that the Syrian government had not used banned munitions and that the attack had been perpetrated by rebels on the ground.
The Syrian Observatory for Human Rights, which monitors the conflict from Britain through contacts inside Syria, said that Thursday’s attack had hit a branch of the Scientific Studies and Research Center, a government agency that the United States has accused of producing chemical weapons. It also hit a storage building nearby where ground-to-ground missiles were kept, the group said.
As is common with strikes in Syria, Israeli officials declined to comment.
But Amos Yadlin, a retired Israeli general and the executive director of the Institute for National Security Studies at Tel Aviv University, wrote on Twitter that the attack had struck a factory that produced precision missiles, chemical weapons and barrel bombs, which are crude explosives dropped from helicopters.
Previous Israeli strikes in Syria have not led to retaliation by Hezbollah or by the Syrian government, presumably because those two groups prefer to focus on winning the war in Syria without getting embroiled in a new conflict with Israel.
The Syrian government once had large stockpiles of chemical weapons, which it agreed to give up under a 2013 agreement between Russia and the United States. That deal was brokered after Syrian forces were accused of launching chemical attacks near Damascus that killed more than 1,000 people.
The agreement was hailed as a diplomatic success by the Obama administration, an achievement now tarred by continued reports of further chemical attacks, indicating that the Syrian government hid some of its chemical stocks.
The United Nations report released on Wednesday said the attack on Khan Sheikhoun, which led President Trump to order cruise missile strikes on a Syrian air base, was just one of at least 20 chemical weapons attacks carried out by Syrian government forces from March 2013 to March 2017.