Syrian rebel forces claimed that 22 people, including nine Iranians, were killed in an overnight strike in northern Syria blamed on Israel, the Qatar-based al-Jazeera network reported Monday.
The figure, which could not be confirmed, was much higher than an earlier report of nine deaths provided by a Syrian watchdog group.
The al-Jazeera report did not cite its sources or give any further details.
Syrian state media has accused Israel of carrying out the bombing of a military position in Aleppo province late Sunday, in what would be a rare Israeli attack so far north in the war-ravaged country.
“The Israeli missiles targeted an Iranian Revolutionary Guard center, near the Neyrab military airport,” said Rami Abdel Rahman, the head of the Syrian Observatory for Human Rights, a Britain-based monitor.
He said those killed included at least six Syrians, but could not specify the nationalities of the remaining fighters.
The position is a logistics hub used to provide equipment and food to pro-regime forces fighting at nearby fronts, but it did not store weapons, Abdel Rahman said.
Earlier Monday, the country’s official news agency SANA reported there was only damage to the site, identified as the Al-Nayrab airbase, adjacent to Aleppo’s international airport.
“The Zionist enemy (Israel)… targeted with its missiles one of our military positions north of the Nayrab military airport, but the damage was only material,” SANA said citing a military source.
Al-Nayrab has in the past been linked with Iran’s Islamic Revolutionary Guards Corps militia.
The Observatory, which relies on a network of sources inside the country, said it had recorded a wave of blasts around Nayrab on Sunday night.
It said that a suspected Israeli missile strike had targeted “positions held by Syria’s regime and its allies at the Nayrab airport” and its surroundings.
The base was reportedly previously struck by Israel on April 29 as part of a large raid that also targeted weapons depots near Hama.
There was no immediate comment from Israel, which rarely confirms such attacks.
Suspected Israeli airstrikes have hit Syrian army positions near Damascus and in the central provinces of Homs and Hama in the past. However, they rarely occur as far north as Aleppo.
The raid came hours before a high-stakes summit between Russian President Vladimir Putin and US President Donald Trump, where Syria and Iran are expected to be on the agenda.
Israel has been pushing Russia to remove Iranian-aligned militia fighters from Syria, and has vowed to stop them from getting a foothold anywhere in the country. Russia has reportedly only agreed to removing them from the Golan border region.
Prime Minister Benjamin Netanyahu, who met with Putin in Moscow last week, said Sunday he had discussed the issue with Trump a day earlier.
Netanyahu reportedly told Putin during their Wednesday meeting that Israel would not challenge Assad’s control of Syria, in exchange for freedom to act against Iran.
On July 8, Israel was accused of carrying out an airstrike on the T-4 military base near Homs, also thought to be used by IRGC fighters.