JERUSALEM — Israeli warplanes struck several military sites in Syria overnight and killed several fighters and civilians, Syrian state media reported on Monday, in what appeared to be a stepping up of Israel’s long-running, partly covert campaign to thwart Iranian military entrenchment in Syria and stop weapon transfers to Lebanon.

The warplanes fired missiles from Lebanese airspace, according to SANA, the official Syrian news agency, which reported that a baby was among four civilians who were killed. The airstrikes hit a variety of targets, according to the Syrian Observatory for Human Rights, a British-based monitoring group identified with the Syrian opposition.

The targets included the headquarters of the Islamic Revolutionary Guards Corps of Iran in the south of the Syrian capital, Damascus; a scientific research center in the countryside around the city; and positions held by Hezbollah, the Iranian-backed Lebanese group, in the mountains near the border with Lebanon, the Observatory said.

The Hezbollah sites that were targeted included ammunition warehouses, resulting in explosions and huge fires, the Observatory reported.