Syria has warned it may strike at rebels hiding in neighboring Lebanon if the Lebanese army does not act, as its patience "is not unlimited," Reuters reported citing the state news agency SANA.

Syria's Foreign Ministry told its Lebanese counterpart late on Thursday that a "large number" of militants had crossed Lebanon's northern border into the Syrian town of Tel Kalakh over the past two days, SANA said Friday, March 15.

"Syria expects the Lebanese side to prevent these armed terrorist groups from using the borders as a crossing point, because they target Syrian people and are violating Syrian sovereignty," the diplomatic cable said.

It said Syria's "patience is not unlimited", even though "Syrian forces have so far exercised restraint from striking at armed gangs inside Lebanese territory."

Fighting near the border resulted in a large number of casualties, SANA said, before the gunmen retreated into Lebanon.