Curfew remained clamped in the Tehsil Khwazakhela for the fourth straight day on Thursday. Security forces bombed the suspected hideouts of local militants with mortar shells. However, no causality was reported. Meanwhile, at least four policemen were killed and 30 others injured when a suicide bomber rammed his explosive-laden vehicle into police headquarter in Mangora on Wednesday night. The injured were rushed to Saidu Sharif Hospital. The blast was so powerful that it caused damages to adjacent building, while power supply to the city was also suspended. Security forces fired shells at the militants' hideouts immediately after the blast. On the other hand, unannounced curfew is still in force in Tehsil Khwazakhela due to which people are facing severe problems.