Four pro-Iran fighters were among five people killed in overnight Israeli strikes in north and northwest Syria, a war monitor said on Saturday.
"Four Syrian pro-Iran fighters were killed in Israeli air strikes on the scientific research centre and warehouses near Safira east of Aleppo," the Syrian Observatory for Human Rights said.
The Britain-based monitor said two other raids further west targeting Saraqeb in Idlib province killed a fifth person.
It said these strikes targeted two headquarters of Syrian regime forces frequented by members of the Iran-backed Hezbollah group.
Late on Saturday, the Observatory reported two Israeli strikes targeting a Syrian army radar position in the southern province of Suweida, without immediately giving further details.
Since Syria's civil war broke out in 2011, Israel has carried out hundreds of strikes in Syria, mainly targeting army positions and fighters including from Hezbollah.
Israeli authorities rarely comment on the strikes, but have repeatedly said they will not allow arch-enemy Iran to expand its presence in Syria.
Its attacks on the country have also increased since the outbreak of Israel's war in Gaza, on October 7 last year, and have intensified even further following the escalation of Israel's aggression on Lebanon, in late September.
Targets for attack have included border crossings between Syrian and Lebanon, which Israel said have been used as supply routes to rearm Hezbollah.
The monitor said the Idlib raids took place near the front line of the rebel group Hayat Tahrir al-Sham (HTS), the main rebel organisation active in the area.
HTS controls swathes of Idlib province and parts of neighbouring Aleppo, Hama and Latakia.
Syria's official SANA news agency also reported the raids, citing a military source.
"The Israeli army launched an air attack from the direction of southeast Aleppo, targeting a number of sites in the Aleppo and Idlib region," it said.
Several soldiers were injured and there were "material losses", SANA added.
It said the strikes took place at 00:45 am (2245 GMT Friday).