Police and residents said that the two groups came across each other after funeral of a man who had allegedly died of fear of arrest after he was booked by the forest department for felling a tree in the disputed forest.
They said the clash started following exchange of harsh words between the rival groups soon after the funeral prayer was offered.
The local people said that one of the groups had migrated from Chiragali village to nearby Katan village because of the dispute over a forest, but they had come over to Chiragali for the funeral.
They claimed that after exchange of harsh words, members of the group who had come from Katan village opened firing on their rivals, killing eight people. One man was also killed from the alleged aggressor group.
Five other people were injured who were taken to the district headquarters hospital in Dir Khas where doctors referred two of them to Peshawar.
District police officer Mian Naseeb Jan confirmed nine people were killed in the clash.
The deceased were identified as Ihsan, Sultanat Khan, Said Ghafoor, Rooz Amin, Mohammad Raziq, Abdur Raheem, Farman, Isa Khan and nine-year-old Jawad.
Police contingents have been sent to the area to arrest those involved in the attack.
