Lebanon says it deployed troops near its border with Syria Sunday after artillery shells hit a Lebanese border village.
One person was killed after shells from Syria hit the town of Qasr, the Lebanese Army said in a statement.
Several homes were destroyed, and three people were injured, the military said.
"Subsequently, army units were deployed widely across the area and took measures in the field necessary to protect people and respond to the source of the attack as appropriate," the statement said.
The Lebanese military did not release additional details about the incident.
Lebanon's National News Agency reported that a 13-year-old was killed when rockets from Syria hit the region Sunday.
Lebanese President Michel Suleiman condemned the violence, saying in a statement on his website that rockets had fallen near Qasr's mosque.
"These kinds of acts have only resulted in the deaths of innocent Lebanese who have nothing to do with the ongoing conflict taking place outside their country," he said.
The war in Syria has been raging since March 2011 when protesters, partly inspired by Arab Spring uprisings in the region, began demonstrating for more freedom.
That movement quickly morphed into a movement against President Bashar al-Assad, who was appointed president by Syria's parliament in 2000 after his father died. The government responded with a brutal crackdown.
In February, the United Nations estimated that 70,000 people had been killed in the fighting.
At least 124 people were killed in violence throughout Syria on Sunday, the Local Coordination Committees opposition network said.
CNN cannot independently verify death tolls or other accounts of violence in Syria.