Israeli strikes killed 71 pro-Iran operatives in the Syrian city of Palmyra, with more than a third of them identified as fighters from Iraq and Lebanon, a monitor said Thursday.
said the death toll has risen to "79 pro-Iran fighters", 53 of them Syrians, 22 foreign nationals "mostly from the Iraqi Al-Nujaba movement", in addition to "four from Hezbollah", updating an earlier toll of 71 dead.
The strikes targeted three sites in the city renowned for its ancient ruins, including one that hit a meeting of pro-Iranian groups with leaders from Al-Nujaba and Hezbollah.
The Observatory is based in Britain and relies on a network of sources on the ground across Syria.
Syria said the Israeli strikes on the central city killed 36 people and wounded more than 50 others, in the latest toll issued by the defence ministry.
"The Israeli enemy launched an air attack from the direction of the Al-Tanf area, targeting a number of buildings in the city of Palmyra," it said on Wednesday.
The strikes targeting Palmyra -- a modern city adjacent to Greco-Roman ruins -- are the deadliest in Syria since a year of cross-border clashes between Israel and Hezbollah intensified in late September.
In a separate statement, the Syrian foreign ministry condemned "in the strongest terms the brutal Israeli aggression against the city of Palmyra, which reflects the continuing crimes of Zionism against the countries of the region and their peoples".
Israel rarely comments on individual strikes in Syria but has repeatedly said it will not allow Iran to expand its presence in the country.
Palmyra, a UNESCO World Heritage Site, was taken over and pillaged by Islamic State fighters at the height of the Syrian civil war.
The director general of Antiquities and Museums in Syria, Nazir Awad, told news agency AFP the city's temples "did not suffer any direct damage" during the latest strikes.
"We need to conduct a survey on the ground to confirm these observations," he added.
This story was edited to add the latest updates on the new toll from the monitor.