KARACHI - Police used water cannons and tear gas to disperse protesting school teachers at the Karachi Press Club as they tried to reach the Governor House.The protesting school teachers demanded the government to issue them appointment letters. The protestor said that they had started their job five year ago in 2007 but the current government and past government had not issued their appointment letters.As the protestors tried to make their way to the governor house, which is a red zone, they were stopped by the police who used water cannons and tear gas. Several protestors were injured when police baton charged to disperse them. Traffic was severely disturbed in the area.Sindh Education Minister Pir Mazharul Haq said that the teachers, who failed in the first phase of job test held by IBA, must stop protesting and start preparing for the next test. He said that these teachers did not fulfill the criteria set by the World Bank. He added that around 19,000 more teachers will be recruited on merit in the province. He was talking to media on Tuesday, while visiting Benazir Bhutto Shaheed Lyari University.