Unidentified warplanes struck a base in eastern Syria on Saturday night, killing seven Iran-backed militiamen, according to a U.K.-based Syrian opposition war monitor.
The airstrikes targeted a base near the town of Al-Bukamal close to the border with Iraq, said the Syrian Observatory for Human Rights (SOAR), according to the AP.
The strikes came days after shipments arrived at the base from Iraq, according to SOAR and Omar Abu Laila, a Europe-based Syrian activist who runs the Deir Ezzor 24 news website.
Abu Laila said Israel had probably carried out the attack, but did provide any evidence, according to the report.
Israel has reportedly carried out numerous strikes against Iranian and Hezbollah interests in the country, and there has been an uptick in Israeli attacks reported in recent months.
Earlier in May, SOAR reported that Israel launched airstrikes in Syria that killed 14 Iranian and Iraqi fighters, and injured others.