Seven people were injured in an explosion at High Energy Material Research Laboratory (HEMRL) in Sutarwadi at 3.40 pm yesterday. According to R K Pande, joint director, HEMRL, the blast occurred when an explosive propellant composition was being tested in a mixer in a remotely controlled experiment.

Around 1,000 people work in the lab, a highly protected area that carries on research on futuristic ballistic weapons and armory. Regional Defence PRO Manish Bharadwaj said, "The mishap took place because sometimes experimental chemicals behave differently," added Pande.

The injured have been admitted to Hardikar Hospital in Shivaji Nagar. HEMRL has appointed a standing committee to probe the mishap. Nitin Ranpise, resident of Pashan area, said the sound of the explosion was so high that it could be heard several kilometers away. "I though it was an earthquake. People were rushing to the spot and I saw ambulances drive out of the lab," said Ranpise.