Latehar (Jharkhand): At least four class 2 students were injured, one of them critically, after a portion of the ceiling of their school's classroom in Jharkhand's Latehar district caved in on Sunday, an official said.The incident took place in Saraidih Urdu Middle School at Pokhrikala in Barwadih police station area, around 180 km from the state capital Ranchi.Around 50 students were in the classroom when the incident happened. Urdu-medium schools remain open on Sundays and are closed on Fridays.Barwadih Block Development Officer Rakesh Sahay said, "Of the four students, one is critically injured, and has been admitted to Medininagar Medical College and Hospital, while the remaining three are undergoing treatment at a local hospital."Md Ajam Khan, the headmaster of the school, said there are only four rooms in the school for a total of 721 children.The condition of all the four rooms is very poor, he added.