Lebanese President Michel Sleiman on Tuesday condemned Syria for carrying out "unacceptable" air strikes inside Lebanese territory, but Damascus denied it was responsible for the attacks.
"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 eastern 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".
But Syria, in its first comments on the attacks, denied it was involved.
"The information being peddled by the Lebanese, Arab and international media claiming that Syria fighter jets bombed inside Lebanese territory is baseless," a foreign ministry official told state news agency SANA.
"The ministry completely denies this information and reiterates that it respects Lebanese sovereignty and remains committed to the security and security of its brother Lebanon," the official said, speaking on condition of anonymity.
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, said the warplanes had targeted two barns used by "armed men" in the Wadi al-Khayl area of Arsal.
Washington also confirmed 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," said State Department spokeswoman Victoria Nuland.