Seven persons were arrested and a huge quantity of detonators and explosive materials were on Wednesday recovered from Gopi Bigaha village in Bihar's Rohtas district. Acting on a tip off,the police raided the village and recovered 3,000 detonators and 90 quintal of ammonium nitrate meant for use in illegal mining of natural resources,SP Manu Maharaj said. The police has arrested seven persons in this connection,he said. The accused were involved in illegal mining earlier,Maharaj said.