The city of Srinagar, the summer capital of the federal territory, is due to host a tourism working group meeting of G-20 members on May 22-24, part of a series of meetings ahead of a G-20 summit in New Delhi in September.
Islamist militants have stepped up attacks this year in the Jammu region, across the mountains from the Kashmir Valley where Srinagar is located.
Ten soldiers and seven civilians have been killed in four attacks in Jammu this year.
Security officials said they fear the separatist militants could try to promote their cause with an attack before or during the G-20 meeting.
“The timing of these attacks is worrisome as they are planned just before the G-20 meeting,” said a senior Indian army officer in the region. He declined to be identified as he is not authorized to speak to the media.
Military and police officers said they had intelligence information that militants might target a military-run school in Jammu and take students hostage.
In response, such schools had been shut and classes moved online until after the G-20 meeting, they said.
Security agencies are not taking any chances in Srinagar, officers said.
Vijay Kumar, chief of police in the Kashmir Valley, told Reuters that commandos had been deployed in the city and members of a counter-terrorism force would be on stationed in various places.
Srinagar has been at the center of the insurgency by Muslim militants against Indian rule since 1989.
Tens of thousands of people have been killed although the violence has been reduced in recent years.
India blames Pakistan for supporting the Muslim insurgents. Pakistan denies that and accuses India of violating the rights of Kashmir’s Muslim people. India denies that.
The nuclear-armed neighbors, who have fought three wars, two of them over Kashmir, both claim the region in full but rule it in part.