The mishap took place as a tree uprooted in a storm and fell on a passing auto-rickshaw trapping six passengers under its weight, the sources said.
Three women, identified as Yashoda Devi, Premsheela Devi and Hussaina Khatun were killed on the spot, three others Meena Devi, Sita Devi and a four year-old girl sustained injuries, they said.
The injured were admitted to a hospital for treatment, sources said, adding that bodies have been sent for post-mortem.