Lebanese President Michel Sleiman on Tuesday denounced as "unacceptable" air raids carried out by Syrian warplanes against targets inside Lebanese territory.
"The president of the republic, General Michel Sleiman, considers Syrian air strikes inside Lebanese territory an unacceptable violation of Lebanese sovereignty," Sleiman said in a statement from his office.
The remarks were the first official Lebanese confirmation of the air strikes a day earlier, which hit the town of Arsal, in east Lebanon, close to the Syrian border.
The statement said Sleiman had instructed Foreign Minister Adnan Mansur "to send a message of protest to the Syrian side so that such operations are not repeated."
On Monday, a high-ranking Lebanese army official confirmed Syrian air strikes along the border area, without saying whether they had struck inside Lebanese territory.
But a security services official on the ground told AFP that Syrian planes had fired four missiles at Arsal, where many residents back the uprising against Syrian President Bashar al-Assad.
Al-Manar television, which belongs to the pro-Syrian regime Lebanese Shiite Hezbollah movement, reported that the warplanes had targeted two barns used by "armed men" in the Wadi al-Khayl area of Arsal.
Washington also confirmed that Syrian forces had fired at northern Lebanon, calling the strikes "a significant escalation in the violations of Lebanese sovereignty that the Syrian regime has been guilty of."
"These kinds of violations of sovereignty are absolutely unacceptable," US State Department spokeswoman Victoria Nuland said.