NEW DELHI — A deadly attack on tourists in Indian-controlled Kashmir has again moved India and Pakistan closer to war as the two rivals downgraded diplomatic and trade ties, closed the main border crossing and revoked visas for each other’s nationals.

India and Pakistan troops exchanged fire in the Jammu and Kashmir region on Friday, according to officials in New Delhi, as relations between the nuclear-armed neighbors continue to plummet after a deadly attack on tourists this week.

The Indian rupee ended weaker in a volatile session on Friday as investors stayed cautious amid fears of an escalation in tensions with Pakistan after a militant attack in Kashmir earlier this week.