Lebanese President Michel Suleiman met with top security officials to discuss border concerns from the Syrian civil war. The government said it was filing a formal complaint against Syria at the Arab League, The Daily Star newspaper reports.
A Syrian rocket attack last weekend left one person dead in the border town of al-Qasr.
"Such practices have led to the killing of innocent Lebanese that have nothing to do with the conflict raging on the other side of the border," Suleiman was quoted as saying.
The Syrian government had warned Lebanon it would take defensive action if anti-regime activity was carried out in the border regions. A Lebanese report on an early April attack by Syria on the border town of Arsal said no military targets were hit when attack helicopter fired two missiles on suspected smuggling routes.
Lebanon's national security has come under threat from the civil war in Syria. March marked the seventh anniversary of the Cedar Revolution in Lebanon, which broke Syria's grip on Lebanese affairs.
Human Rights Watch accused Syrian forces of conducting airstrikes against civilians, violating the laws of war and committing war crimes. At least 70,000 people have died as a result of civil war, now in its third year.