Heavy firing exchanges between the security forces and a militant started Friday morning near the international border in Jammu and Kashmir, hours ahead of Prime Minister Narendra Modi's visit here.A group of heavily-armed militants infiltrated into the Indian side at Arnia in Jammu district Thursday. The security forces took them on and four militants were killed.A total of 10 people, including four civilians, were killed in this operation in the R.S. Pura area Thursday.Sources said the lone surviving militant is presumed to be firing Friday from an abandoned army bunker in Pind Khote village of the R.S. Pura area.A senior police officer said the operation to nab the militant is on going and heavy firing is under way.Police also said another body was found during an search of the area.Modi is scheduled to arrive here around noon Friday to address election rallies before the second phase of assembly elections Dec 2.