The Election Commission of India on Saturday banned politicians from entering West Bengal’s Cooch Behar district for the next three days, after four people were killed in firing by central forces during the fourth phase of voting for Assembly polls, PTI reported.

The poll body also extended the silence period for the next phase of the West Bengal elections, which is scheduled to take place on April 17, from 48 hours to 72 hours. This will cut short the campaigning period.

The Election Commission also directed the special police observer and the chief electoral officer of Bengal to keep updating it about the developments in Cooch Behar over the next 72 hours, NDTV reported.

It had said earlier on Saturday said that the clashes took place outside a polling booth in the district after local residents attacked security forces due to a misunderstanding. The poll body added that Central Industrial Security Force personnel were trying to help a boy who had fallen ill near the polling booth in Sitalkuchi, but local residents thought that he was being beaten up and called about 300 to 350 villagers to the spot.

The Election Commission said that security forces had no option but to open fire to save their lives and government property. Voting was adjourned at the polling booth after the violence.

The poll body also asked the Union home ministry to send 71 more companies of Central Armed Police forces to West Bengal. At present, 1,000 companies are stationed in West Bengal.

The Trinamool Congress and the Bharatiya Janata Party blamed each other for the incident. Chief Minister Mamata Banerjee said it was a “planned attack” and accused the central forces of murdering people. She said that Bengal Police Crime Investigation Department would conduct an inquiry into the incident.

“Home Minister Amit Shah is completely responsible for today’s incident and he himself is the conspirator,” the chief minister said. “I don’t blame central forces because they work under Home Minister’s order. We will demand his [Amit Shah] resignation.”

Prime Minister Narendra Modi, on the other hand, criticised Banerjee and her party. “What happened in Cooch Behar is sad...I offer condolences to bereaved families,” he said. “Mamata Didi and her goons are jittery because of groundswell of support for the BJP.”