The CBI filed the fourth chargesheet in the ongoing probe into the post-poll violence cases in Bengal, sources said on Saturday.

The chargesheet was filed at Krishnanagar court in Nadia district in connection with the killing of a BJP worker allegedly by Trinamul Congress members, they said.

The chargesheet contains names of the two accused allegedly involved in the murder of the BJP worker after the Assembly election results were announced on May 2, they added.

The Calcutta High Court last month directed the CBI to probe the post-poll violence cases.

So far, the CBI has filed 34 FIRs in connection with murders and other heinous crimes perpetrated after the election results were announced.

The agency has already filed three chargesheets in different courts in connection with incidents that happened in Bhatpara in North 24 Parganas, and Nalhati and Rampurhat in Birbhum district.