A page from the local gurudwara's holy book was torn off and found on the streets, they said.
Senior police officials have reached the spot as also Shiromani Gurudwara Parbandhak Committee members Gurbaksh Singh Khalsa and Sukhdev Singh Bhaur.
A case has been registered and investigation is on, police said.
Several parts of the state had witnesses protests last year against a series of incidents of desecration of the Sikh holy book.