Two Class 4 students of a private school in Hyderabad died on Thursday when the roof of a stage where they were practising karate collapsed, NDTV reported. Five more students at New Century school in the city’s Kukatpally area suffered injuries, with two of them in a critical condition.

A student said about 25 children were helped out of the rubble. “We will register a case of negligence against the school authorities,” The Times of India quoted Madhapur Deputy Commissioner of Police A Venkateswara Rao as saying.

The police have arrested one of the school’s directors, and are trying to find out if the school had a safety certificate from the district education officer. The principal is on the run, according to NDTV.