Syrian aircraft bombed two locations inside Lebanon on Monday, the deputy mayor of the eastern town of Arsal told the Lebanese-based Daily Star.
Washington described the act as a "significant escalation" of violations of Lebanese territories by Damascus.
Ahmad al-Fliti, the deputy mayor of Arsal, told The Daily Star that Syrian warplanes dropped two bombs on the eastern border areas of Kherbit Youneen and Wadi al-Khayl, at least 5 kilometers into Lebanese territory, leading to material damage.
No casualties were reported.
The U.S. State Department confirmed that Syrian aircraft, both jets and helicopters, had launched rocket attacks on Lebanese locations.
"Regime jets and helicopters did fire rockets into northern Lebanon impacting Wadi al-Khayl, near the border town of Arsal,” State Department spokeswoman Victoria Nuland told reporters.
“This constitutes a significant escalation in the violations of Lebanese sovereignty that the Syrian regime has been guilty of," she added.
Although used for agricultural purposes, the two sites targeted by the Syrian aircraft are known to be used as channels for smuggling arms and gunmen across the border.
Monday’s was the second Syrian aerial attack on Lebanese territory since the uprising against President Bashar Al-Assad, noted The Daily Star.
In September 2012, a high-ranking security source told the newspaper that two Syrian warplanes bombed the farm fields of Khirbet Dawoud, in northeast Lebanon.
Tensions between the two neighbors have spiked after Damascus recently warned Beirut it would attack rebels in Lebanon if incursions into Syrian territory continued.
In a letter sent to Lebanon’s Foreign Ministry last week, Damascus said Syrian troops were still exercising self-restraint by not striking “concentrations of armed gangs inside Lebanese territory in order to prevent them from crossing into Syrian territory.”
However, the letter warned, “This will not last indefinitely.”
The Syrian threat prompted the country’s opposition to repeat its call for the deployment of further Lebanese soldiers in places that have come under fire from Syria as well as extending the mandate of the United National Interim Forces in Lebanon to include the 550-kilometer-long border with Syria.
Over the past two years, the Syrian military has attacked Lebanese border towns, leading to fatalities and forcing some residents to flee their homes, reported The Daily Star.
Separately, Prime Minister Najib Mikati called on France’s assistance to boost the Army’s capabilities.
In a phone conversation with French Foreign Minister Laurent Fabius, Mikati “reiterated Monday his demand for France to support the Lebanese Army and strengthen its capabilities,” the report said.
According to Mikati’s office, the prime minister also expressed “hope France, as well as the international community, would take the initiative to support Lebanon in its efforts to provide relief to Syria refugees, particularly given the [refugee situation] has exerted pressure on Lebanon beyond its abilities.”
Fabius reiterated France's commitment to stability in Lebanon and its support for the Lebanese government’s policy with regard to the situation in Syria.