Nihang Charanjit Singh (40) slashed Nihang Piara Singh's (45) neck with a sharp weapon yesterday after a dispute, police said.
The dead man was the chief sewadar (religious volunteer) of the Gurdwara Bibangarh.
"Charanjit, after killing Piara, climbed on the 'gumbad' (dome) of the gurudwara. It took a lot of effort to bring him down and arrest him," a police official said.
Police have registered a case of murder and launched an investigation into the case, the official said, adding that the accused was being questioned.