BEIRUT — At least three Lebanese Army soldiers were killed Friday in a shootout as they tried to arrest a resident of a village that has become a hub of refugees and where Syrian rebel fighters often cross the border. Their target was also fatally shot.

There were conflicting reports about the nature of the clash, in which security forces were ambushed as they pursued a wanted man, but the episode played into fears that the accelerating influx of Syrians could spread the conflict into Lebanon.