Six people were killed and eight others injured in a helicopter crash in Pakistan's northwest Khyber Pakhtunkhwa province on Saturday, police sources said.The chartered helicopter carrying staff of Mari Petroleum Company Limited was on its way to Shewa camp when it met a technical fault and crashed in North Waziristan district of the province, police sources in North Waziristan told Xinhua.Police said that six of the passengers died on the spot, while eight others sustained critical injuries in the crash.An investigation has been launched into the incident. Following the incident, rescuers and security personnel reached the area and cordoned it off.Source: The Namibia Press Agency