At least seven people were killed and dozens injured in two bomb blasts in southern Turkey on Wednesday, a senior official said.One of the explosions targeted a police bus outside Mardin State Hospital in the town of Kiziltepe, on the Turkish border with Syria, CNN reported.The blast killed three people and wounded at least 30 people.Simultaneously, a separate car bomb on a bridge in the nearby city of Diyarbakir killed four people and injured at least 13, added the official.Initial assessments indicate Kurdish militants were behind both attacks, the official said.