BEIRUT — Syria’s military said Israel struck a military installation southwest of Damascus International Airport before dawn Thursday, setting off a series of explosions and raising tensions further between the two neighbors.

Apparently seeking to interrupt weapons transfers to the Hezbollah group in Lebanon, Israel has struck inside Syria with increasing frequency in recent weeks, making the war-torn country a proxy theater for Israel’s wider war with Iran.

The increasing tempo of attacks risks inflaming a highly combustible situation drawing in Israel, Syria and the Iranian-backed Hezbollah, a staunch ally of President Bashar Assad’s government with thousands of fighters in Syria. Israel’s military said later Thursday that its Patriot Missile Defense system intercepted an incoming projectile from Syria over the Golan Heights.

An Israeli defense official said the Patriot hit a drone, and the military is checking if it was a Russian craft that entered the Israeli side by mistake or if it was Syrian. He spoke on condition of anonymity in line with protocol.

Both the Syrian government and Hezbollah, however, are mired in the country’s 6-year-old civil war and are unlikely to carry out any retaliation that may ignite a bigger conflagration with Israel.

“Iran and Hezbollah are overstretched, and it’s not clear they can afford to gamble with a direct showdown with Israel now,” said Maha Yahya, director of the Carnegie Middle East Center. “Iran knows no matter how powerful they’ve become, they can’t be fighting on two fronts at the same time.”

Israeli Minister of Intelligence Yisrael Katz would not comment directly on the incident but said any similar strike would be in line with established policy to interrupt weapons transfers.

“It absolutely matches our declared policy, a policy that we also implement,” Katz told Israel’s Army Radio.

Just before the apparent Israeli missile strike, at least three cargo jets from Iran probably landed at the Damascus airport, said Ian Petchenik, a spokesman for the flight-tracking website FlightRadar24. They include an Il-76 flown by the Iranian cargo company Pouya Air that “was last tracked over Iraq headed towards Damascus,” he said.

It’s unknown what they were carrying. Passenger flights and civilian cargo jets continue flying into Damascus, although there’s suspicion that some commercial flights serve as cover for weapons transfers from Iran.

The Washington-based Foundation for Defense of Democracies, a right-leaning think tank that has criticized the nuclear deal Iran struck with world powers, has said Pouya Air is the latest name for a long-sanctioned airline. It also has accused Pouya Air of funneling arms from Iran into Yemen to supply Shiite rebels there.

Emanuele Ottolenghi, a senior fellow at the foundation, said he tracked a fourth cargo flight from Iran to Syria on Wednesday night, an Airbus A300 operated by Mahan Air, which is suspected of ties to Iran’s paramilitary Revolutionary Guard. He also called one of the cargo flights, a Qeshm Fars Air Boeing 747, especially suspicious because the airline stopped operating in 2013, only to resume flights to Damascus three weeks ago.

“We don’t know for sure, but let’s say that we can fairly safely assume that the weaponry and fighters reach Damascus through these daily flights,” Ottolenghi told The Associated Press.

The explosions near Damascus reverberated across the capital, seat of Assad’s power.

Syria’s state-run SANA news agency said Israel had fired several missiles from inside the occupied Golan Heights, 37 miles south of Damascus, striking a military installation southwest of the airport that serves both military and civilian flights. It reported damage but no casualties.

“The buildings shook from the force of the blast,” said a media activist who goes by Salam al-Ghoutawi of the Ghouta Media Center in the opposition-held northeastern suburbs, about 9 miles from the airport. He said he heard the roar of jets in the distance.

Explosions were silhouetted against the night sky in a video published by the center. Debris was seen flying out as the explosions illuminated a sizable cloud nearby.

Hezbollah’s al-Manar media station reported a blast at fuel tanks and a warehouse next to the airport, which is 16 miles east of central Damascus.

The Syrian military said in a statement the attack sought to “raise the morale of terrorist groups” the government maintains are fighting Assad’s forces. It made no mention of whether it would respond.