BSF patrolling party sighted a group of militants entering close to the international border fence, and opened fire on them.
The fire was opened to keep the infiltrators off the fence and to stall their intrusion bid.
"There was fire from Pakistani side. It is difficult to say if these were Pakistani Rangers or the militants as the visibility was almost zero," a BSF official was quoted by news agency as saying.
"The firing continued from around midnight to 4am."
This is the sixth attempted infiltration from across the border in recent months.
Defence minister A K Antony on Wednesday, Jan 13 said that he had asked security forces to increase vigil to foil infiltration attempts.
He had also stated that Pakistan was backing the infiltration attempts on the border.