A National Investigation Agency (NIA) team was on Monday dispatched to Patna to formally take over the probe into the Patna serial blasts. At least three suspects have been arrested so far in connection with the blasts.

“A team from the Lucknow unit, headed by an officer of Deputy Inspector-General rank, will conduct the investigations. Some officers from the NIA headquarters are also being sent to assist the team. The probe will be initiated formally once the case file is handed over to the team by the Bihar Police. The papers may be transferred to us by Tuesday,” said an NIA official. The team boarded a flight to Patna on Monday evening.

The agency had earlier sent a team to examine the explosion sites, hours after the blasts on October 27.

The Bihar Police had earlier received the Centre’s order for handing over the investigation to the NIA on October 31. However, agency sources said it was yet to receive all the documents pertaining to the probe conducted so far by the Patna Police.

“We have received the order from the Centre. I have also passed an order for the formal handover of the case. If the case diary has not yet been given, then the Bihar Police are investigating the case,” Bihar Director General of Police Abhayanand told The Hindu on Monday.

Additional Director General (Railways) P.N. Rai said the probe had not yet been handed over formally to the NIA. “It will either happen tonight (Monday) or Tuesday,” he said. Some officers from the local police would also assist the NIA. Another NIA team has also conducted searches in coordination with the Jharkhand Police in Ranchi following purported disclosures of the arrested suspects that several members of the module, which triggered synchronised bombings, are from Ranchi.