SOUTH WAZIRISTAN, Aug 25: Four people were killed and three others critically injured in an exchange of fire between the Jani Khel Wazir tribe of North Waziristan and the Malkshai Mehsood tribe of South Waziristan here on Friday. The two tribes have long been locked in a dispute over the ownership of a mountain in Shawal near the Pak-Afghan border. Those killed in the exchange of fire included a 10-year-old girl belonging to the Jani Khel Wazir tribe.—Online