The injured have been admitted to Apollo Hospital, Chennai.

The blast occurred when a test propellant segment caught fire while being prepared for transportation after curing. The solid propellant is hydroxyl terminated poly butadiene (HTPB) which powers India's space missions.

The blast also damaged the building in which the operations were being carried out.

According to Indian Space and Research Organisation (ISRO) operations are on to rescue the others. Emergency action has been taken to approach the building and clear the debris to reach the people inside. A high level committee has been constituted to look into the matter.

SPROB is one of the biggest facilities in the world. Commissioned in 1977, the facility is spread over 25 sq.km.

G Madhavan Nair, chairman, ISRO, has rushed to Sriharikota to personally supervise the operations. According to him, the accident will not impact ISRO's launch plans.