Bhubaneswar: Four persons were injured in a crude bomb explosion in Sundarpada area here on Tuesday, police said. According to the police, the incident took place at Azad Nagar in Airfield police station here when some people were binding a crude bomb illegally at the rooftop of a rented house. “Four persons, including S Mallik, who has criminal background, were injured in the bomb blast. Seven cases are pending against S Mallik in Nayapalli, Maitri Vihar and Khandagiri police station area, Meena said. “We will interrogate the injured persons to find out the involvement of any other person in illegal bomb making,” the DCP told media persons.