The United Arab Emirates has secretly carried out airstrikes against Islamist militias in Libya using bases in Egypt, two US officials said Monday.
"The UAE carried out those strikes," one of the officials told AFP on condition of anonymity, confirming a report in The New York Times.
The United States did not take part or provide any assistance in the bombing raids, the two officials said.
The first airstrikes took place a week ago, focusing on targets in Tripoli held by the militias, according to the Times.
A second round was conducted south of the city early on Saturday targeting rocket launchers, military vehicles and a warehouse, according to the newspaper.
Those strikes may have represented a bid to prevent the imminent capture of the Tripoli airport, but the militia forces later prevailed and seized control of it.
The UAE provided the military aircraft, aerial refueling planes and aviation crews to bomb Libya, while Cairo offered access to its air bases, the paper said.
Asked about the details of the Times account, the two US officials said the report was "accurate."
But it remained unclear whether and to what degree Egypt and the UAE had informed the Americans in advance of the airstrikes.
The revelation of the attacks marked a dramatic expansion of the conflict and came as the United States and its European allies denounced the "escalation of fighting and violence" in Libya and urged a democratic, peaceful transition.
A joint statement signed by Washington, Paris, Berlin, Rome and London said that "outside interference in Libya exacerbates current divisions and undermines Libya's democratic transition."