Syrian security forces infiltrated the Bekaa border town of al-Qaa on Tuesday, said various media reports.
Local residents said that clashes ensued between the forces and members of the Syrian opposition.
Two Lebanese officials, one from the police and another from the military, however denied to the Associated Press that the Syrian troops had entered Lebanon.
They stated that the clashes on the Syrian side of the border started on Tuesday in al-Qaa area, adding that bullets struck the Lebanese side of the border.
The National News Agency confirmed the security reports denying the Syrian infiltration, stressing that the Lebanese army had deployed along the border in anticipation of any security development.
It added however that a Lebanese citizen was wounded by a stray bullet from Syria as a result of the clashes taking place along the Syrian side of the border.
Earlier on Tuesday, MTV reported that the Syrian troops had fired rockets towards al-Qaa, forcing residents to take shelter in their homes.
The Syrian Observatory for Human Rights reported that fierce clashes erupted between Syrian regime forces and rebel troops near the border with Lebanon.
Rami Abdul Rahman, head of the Britain-based group, confirmed that the clashes were taking place in al-Qaa region.
There were no immediate reports of casualties.
A resident on the Lebanese side of the border told AFP the clashes were taking place inside Syrian territory.
“We can hear gunfire and explosions,” he said.