At least 18 people were killed and over 50 were injured on early Saturday when a powerful explosion ripped through a crowded market in Kurram agency, Pakistans northwestern tribal region, officials said.The explosion occurred early morning around 8.50am in the northwestern city of Parachinar at Eidgah market, Geo TV reported. An eye witness said that a large number of people were present in the market at the time of the blast .The political administration in Kurram tribal agency confirmed the death toll and said the injured were shifted to the agency headquarters hospital. At least 10 persons were said to be in critical condition.However, the Inter-Services Public Relations, the military's media wing, said that six people were killed and 20 were injured in the blast, which it said was carried out through an improvised explosive device (IED).Parachinar is the administrative headquarters of Kurram agency and is located close to the Afghan border. It has suffered terrorist attacks in the past as well. A similar blast at the Eidgah Market in December 2015, killed 25 people and injured 70 others.