BEIRUT: A missile attack on government outposts in northern Syria killed more than a dozen pro-government fighters, many of them Iranians, a war monitoring group and an Iranian news agency said Monday. The strikes came amid soaring tensions between regional archenemies Israel and Iran.

There was no official confirmation of the death toll or what was the target. The Sunday night strikes sparked speculation on who carried it out, with most reports suspecting Israel was behind it.

Syrian state TV called it a “new aggression on military positions” in Hama and Aleppo provinces but was not specific. Activists said there was a spectacular explosion at an arms depot and military compounds where Iranian fighters are based. The explosion was large enough to be picked up by monitors as a magnitude 2.6 earthquake.

The Syrian Observatory for Human Rights said 26 pro-government fighters were killed, most of them Iranians, with only four Syrians among the dead. It said the arms depot contained surface-to-surface missiles belonging to Iranian militias in Hama province. Another attack hit near a military air base in Aleppo province, the Observatory said.

It added that the death toll could rise, since 60 fighters were wounded and several others remained missing.

A member of an Iranian-backed Iraqi militia operating in Syria confirmed the attack on the Hama facility and put the death toll at 36, including 10 Iranian advisers. The official spoke on condition of anonymity because he was not authorized to talk to the media.

Iranian media gave conflicting reports: One semiofficial news agency said there were no Iranians killed, while a second one said 18 were killed.

The arms depot in Hama, known as Brigade 47, is one of the largest bases housing Iranian-affiliated forces and equipment, according to Jamil al-Saleh, commander in the opposition Tajammu al-Ezzat rebel group. He said the province has at least five other bases where Iranians are deployed alongside Syrian-allied militias.

The two airstrikes were near rebel areas, he added.

“It was like an earthquake hit Hama,” al-Saleh said by telephone from Hama province. He and the Observatory said they suspect Israel was behind the attack.

There was no immediate comment from Israel, which rarely confirms or denies its attacks.

The attack came hours after Israeli Prime Minister Benjamin Netanyahu talked by phone with President Donald Trump.