At least four people were killed and seven others injured in a blast which went off Monday evening at a bazaar in Peshawar,a private TV reported. According to the reports, the blast took place at Matni bazaar in Peshawar. Police sources said that the attack was designed to target at a peace committee located near the blast site. A commander of civil militia was reportedly killed during the blast. All the injured people including three children have been shifted to hospital. No group has claimed responsibility for the blast. This is the fourth blast that took place on Monday in Pakistan. All the four blasts occurred today in the country's northwest region which is frequently attacked by terrorists due to the fact that many militants are hiding in this area which is adjacent to Afghanistan.