MASYAF, Syria, Sept 9, (AP): The number of people killed in overnight Israeli strikes in Syria has risen to 18 with dozens more wounded, Syria's health minister said Monday - the largest death toll in such an attack since the beginning of the war in Gaza.

One of the sites targeted was a research center used in the development of weapons, a war monitor said. Syrian officials said civilian sites were targeted. Israel regularly targets military sites in Syria linked to Iran and the Lebanese militant group Hezbollah. Those strikes have become more frequent as Hezbollah has exchanged fire with Israeli forces for the past 11 months against the backdrop of Israel’s war against Hamas - a Hezbollah ally - in Gaza.

However, the intensity and death toll of Sunday night's strikes were unusual. There was no immediate comment from the Israeli military. Israel has carried out hundreds of strikes on targets inside government-controlled parts of war-torn Syria in recent years, but it rarely acknowledges or discusses the operations.

The strikes often target Syrian forces or Iranian-backed groups. Israel has vowed to stop Iranian entrenchment in Syria, particularly since Syria is a key route for Iran to send weapons to Hezbollah. Israeli strikes hit several areas in central Syria, damaging a highway in Hama province and sparking fires, Syrian state news agency SANA said. Speaking to reporters, Syrian Health Minister Hassan al-Ghabbash described the strikes as a "brutal and barbaric aggression.”

He said the death toll had risen to 18 with nearly 40 wounded. The Syrian Observatory for Human Rights, a UK-based war monitor, said 25 were killed, including at least five civilians, while the others included Syrian army soldiers and members of Hezbollah and other Iran-linked armed groups.

One strike targeted a scientific research center in Masyaf, and others struck sites where "Iranian militias and experts are stationed to develop weapons in Syria,” the observatory said. It said the research center was reportedly used for developing weapons, including short- and medium-range precision missiles and drones. Minister of Electricity Mohammad al-Zamel said the strikes had caused "truly significant” damage to water and electricity infrastructure.

"This brutal attack targeted civilian targets, and the martyrs were mostly civilians, as were the wounded,” he said. Local media also reported strikes around the coastal city of Tartous, which the observatory said were the result of air defense missiles falling. On Monday afternoon, a charred car remained at the scene of one strike and smoke was still rising from some spots where fires had been put out.