Indian security forces have imposed tight security restrictions in the Kashmiri city of Srinagar ahead of Wednesday's eightieth anniversary of a violent crackdown on Kashmiri Muslims in the city.

Kashmiri separatist leaders have called for a strike and public processions to commemorate the 1931 killings of 21 Kashmiri Muslims who were revolting against the rule of Kashmir's Hindu king.

Indian authorities have placed key separatist leaders under preventative house arrest ahead of the anniversary. Police are also occupying the cemetery where the separatists are buried. Police say they are trying to keep the demonstrations from turning violent.

On Wednesday, several pro-Indian politicians marked the anniversary by leaving flowers as tributes to those who were killed. Both Indian and Pakistan-controlled areas of Kashmir observe July 13 as “Martyr's Day.”

Muslim separatists have been fighting for Kashmir's independence from Hindu-majority India or a merger with Muslim-majority Pakistan. Thousands have been killed in the insurgency.

Kashmir is divided between India and Pakistan and claimed in full by both.