Kolkata: The four people arrested from Mumbai in connection with the Birbhum killings were brought back to Kolkata on Friday morning by the CBI, an official said.
They were brought back to Kolkata on transit remand, granted by a Mumbai court till April 10, he said.
"We will be taking them to Rampurhat later in the day to speed up the investigation. They will be grilled along with other accused arrested there," the official told PTI.
The CBI on Thursday arrested the four persons -- Bappa, Shabu, Taj Mohammad and Serajul -- from Mumbai where they fled to following the massacre in Rampurhat's Bogtui village on March 21. These were the first arrests made by the central agency after taking over the probe.
Nine people died of burn injuries after their houses in Bogtui were allegedly firebombed following the murder of local TMC leader Bhadu Sheikh.
The CBI took over the investigation of the case, following an order of the Calcutta High Court. The agency at present has the custody of at least 10 people who were arrested by the police in connection with the killings. Among them is then TMC block president Anarul Hossain.