However, the urn containing the relics of the Buddha are safe.
The heist came to light this morning when the museum staff opened the 'Bronze Gallery' housing 'ashtdhatu' (alloy of eigh metals) artefacts after it had closed on Sunday evening, Director of Museums of Bihar Sahdev Kumar told PTI.
As the museum is closed on Mondays, the theft came to light only this morning.
The stolen articles included a foot high 'ashtdhatu' statue of the Buddha and the rest between four and six inches.
The statue and figurines crafted in 'ashtdhatu' had been recovered during excavations at Kurkihar in Gaya district decades ago.
Asked about the monetary value of these articles in the international market, Kumar said "How can one fix any value to the invaluable. Those were invaluable possessions. Their cost may run into a few crores of rupees or a few hundred crores in the international market...Nobody knows."
He said four statues that were to be sent to Belgium for a festival a few months from now and kept in the same gallery, were untouched.
It was reliably learnt that the insurance companies had quoted a premium of about Rs 50 crore for insuring the four statues, including that of the Buddha in 'bhumisparsha' (touching the mother earth) posture.
Police said the thieves, whose number could not be ascertained, climbed to the first floor from the northern side of the building, sliced two bars in the window using a saw, bent those to gain access to the gate of the 'Bronze Gallery' where they broke open the lock and decamped with the statues.
"The statues were some of the most cherished symbols of national heritage," Kumar said.
The locks were shown to the mediapersons at the museum.
While the Inspector General (headquarters) Anil Sinha felt that the complicity of the museum staff could not be ruled out, Kumar thought otherwise.
"The theft occurred on Sunday night after the charge of the museum was handed over to the five-member police team. Every night the charge of the museum is given to them and no no museum staff is there," he said.
Today's theft was a cause of embarassment to the state government as the Singaporean Minister of State for External Affairs Balaji Sadashiv was scheduled to visit the museum.
Sadashiv and his six-member team had to cancel the visit due to the heist.
Asked if he had informed the CBI or the Archaeological Survey of India about the incident, Kumar said "It is not my job. The state Minister of Culture and the concerned departmental secretary took stock of the situation. They must have reported the matter to the concerned authorities."
Asked whether an international or inter-state gang could be involved in the theft of the statues, Sinha said "all aspects of the heist are being looked into. Every angle is being focussed on."
"We are taking care to ensure that these artefacts are not allowed to cross the international border and to fall in the wrong hands...We have received vital clues but we cannot tell you as it would hinder investigation."
Chief Minister Nitish Kumar, when asked about the incident, termed it as "very unfortunate" and said an independent inquiry would ascertain the facts.
"I am shocked learn about it. The matter merits investigation by an independent Central agency," he said in an apparent indication that the government would recommend a CBI probe.