Patna: The two bombs that National Security Guard experts exploded safely in Bodhgaya on Sunday could have caused major damage to the Mahabodhi Mahavihara.

A five-member NSG team reached Bodhgaya late on Saturday night. "The tremor of the blasts was felt in a radius of over half-a-kilometre, which means they could have caused extensive damage to the temple had they exploded where they were planted," said an investigating officer.

The technology used in making the bombs pointed to the involvement of a terror group, the officer said. "They are IEDs (improvised explosive devices), but of inferior quality," said the officer.

The bombs, each weighing 8 to 10kg, were recovered from near the gates of the Unesco World Heritage Site on Friday night hours after a low intensity thermos bomb exploded near a tea stall outside the temple premises. A forensic expert said this was the first time a thermos bomb has been found in Bihar. IG, Patna zone, Nayyar Hasnain Khan, who returned to Patna after review of security arrangements for the Dalai Lama, said the cops have gathered leads.