Go to the hospital first. They should call the police for you. That way you not only have a record of the dog attack but you can get antibiotics. You always need antibiotics if bitten by a human or animal. Give the police the names and/or addresses of the other people attacked so you can all press charges against the owner. If all comes through they will probably force them to put down the animal.
If a dog bites you and has previously bit others, you may need to report the matter to the authorities and record a statement. If the dog bit you outside the owner's compound, the dog may be put down. You should also seek medical attention for the injuries inflicted.