Government forces implemented a security lockdown in downtown Srinagar, the urban heart of anti-India protests, as they warned residents to stay home.
Road traffic was sparse, with buses staying off the roads and few cars venturing out.
Authorities detained dozens of activists overnight and put separatist leaders under house arrest to stop them from staging the protest march. They also ordered schools and colleges to be closed for the day.
Mr. Modi arrived in the remote mountainous Ladakh region bordering China and Pakistan, where he inaugurated work on a strategic tunnel connecting the cold desert region with the Kashmir Valley.
Later in Srinagar, Mr. Modi inaugurated, remotely, a controversial hydroelectric power project built in the Gurez Valley, just a few hundred yards from the highly militarized Line of Control that divides Kashmir between India and Pakistan. He dedicated the power station to the nation at a lakeside venue.
“Every stone, every weapon picked up by misguided youths destabilizes their own Jammu-Kashmir,” Mr. Modi said in his speech, referring to anti-India protesters. “Every issue, every problem has one solution: development, development and development.”