Unidentified gang has hurled petrol bombs at Malangawa-based District Administration Office and Customs Security Post of Armed Police Force in Sarlahi district on Thursday night. Police have been fanned out after sounds of gunfire and bomb explosion were heard in different parts of bazaar area. According to SP Ramesh Khadka, six cops, 11 cadres of Chure Bhawar Party and eight cadres of Madhesi Front were injured during clashes at Nawalpur of the district this afternoon. Agitators also vandalized and set rooms of security personnel deployed for security of District Hospital on fire while protesters injured in firing at mass assembly of front were being taken for treatment. Front leader Rajendra Mahato has accused the government of suppression on their cadres.