The swedish singer Carla was making no comment yesterday after an incident at Mexico City Airport in which she hit out at a press photographer, breaking his nose. The attack took place at the singer was arriving from Sweden for a countrywide tour. Witness said that Carla posted for the waiting photographers with her 6-year-old daughter who was accompanying her, but when one photographer, American Brad Puttnam, kept taking photographs of the mother and daughter, the singer lashed out. Puttnam is threatening to sure. The singer's publicity aide says that Carla regrets the incident and just wants to be left alone