At least four persons of a family were drowned and five others went missing when a boat capsized in a tank near Gulbarga yesterday. Police said the family had gone for a joy-ride to the tank at Kaja Kotanur, 15 kms away from Gulbarga on a picnic, when the boat capsized.Four bodies have been recovered and search is on for the missing persons. One person swam to safety and another was rescued.