The Central Bureau of Investigation on Sunday named 21 people as accused in the Birbhum violence, in which eight people were beaten and charred to death earlier this week on Tuesday, triggering political furore.
The list of accused is the same as that of the state police, according to media report.
Around 20 people have been arrested after six women and two children -- mostly of members of a single family -- were locked in their homes and burnt alive by a mob at the Bogtui village near Birbhum's Rampurhat town.
The attack was followed by the murder of a local Trinamool Congress leader, Bhadu Sheikh, who died in a bomb attack.
West Bengal chief minister during her visit to Bogtui, had said that no one would be spared. She had also promised that her party's block president Anarul Hossain will be arrested for not informing the police and helping them in preventing the
crime.
"I never believed something so barbaric can happen in modern Bengal. Mothers and children were killed. Your family members died but it is my heart that was crushed," Mamata Banerjee said, surrounded by the family members and relatives of those killed, besides villagers. Alleging a bigger conspiracy, she called for "stringent action" and said the police would investigate all angles.
While being taken away for questioning by the CBI, Anarul Hossain speaking to the reporters said, "It is a conspiracy by my opponents."
The team of CBI has set up a temporary camp at a government guest house in Rampurhat. Led by senior officer Akhilesh Singh, the team has now split up and started work by visiting the home of Sona Sheikh, whose house was set ablaze.
The Calcutta High Court on Friday handed over the investigation into the Birbhum killings to the central agency and set a deadline of April 7 to submit its progress report.