The incident took place in the afternoon at Palar village under Tappal police station area when they went in the tubewell to install a pipe and inhaled the poisonous gas, they said.
The deceased have been identified as Prempal Sharma (30), Hemlata (28), Gular Singh (28), Shiv Kumar (27) and Yaduvir Singh (26), police said, adding the bodies have been sent for postmortem.