Nine jihadists with the Al-Qaeda-linked Al-Nusra Front, among them four foreigners, were killed on Sunday in a US-led coalition air strike in Syria near the Turkish border, a monitor said.
The Britain-based Syrian Observatory for Human Rights said the death toll may rise as more bodies may be buried under rubble.
"Nine members of the Syrian branch of Al-Qaeda, including four foreigners, were killed on Sunday at Adme during coalition raids on a headquarters of the group," Observatory chief Rami Abdel Rahman said.
He said the headquarters was spread across several buildings in the border area.
Residents told AFP that at least six salvos of missiles destroyed three houses less than a kilometre from the town centre.
They said practically nothing was left of the buildings, which had been occupied by Al-Nusra Front members.
"There are several victims among the Islamist fighters. There were foreigners there, but mostly Syrians," one said.
Al-Nusra Front jihadists are currently a prime coalition target.
Their military chief Abu Hammam al-Shami and several of his lieutenants were reported killed last week in northwest Syria where the group is trying to establish an Islamist "emirate".
Abdel Rahman said Shami died on Thursday from wounds possibly sustained in a February 27 coalition raid in Idlib province.