MASNAA, Lebanon – Syrian security forces killed as many as 20 Lebanese gunmen who were fighting alongside rebels in Syria on Friday, raising tensions amid mounting fears that the Syrian civil war is enflaming the region.

The Lebanese security officials said the gunmen were killed as they tried to enter the Syrian town of Tal Kalakh, near the Lebanese border. The officials asked that their names not be used because they were not authorized to speak publicly.

Syrian state-run media also reported that Lebanese gunmen were killed. But the SANA report said there 17 – not 20 – fighters. The discrepancy could not immediately be reconciled.