Bengal Governor Jagdeep Dhankhar on Tuesday said Prime Minister Narendra Modi called him and expressed anguish over the law and order situation in the state following reports of post-poll violence from several districts.

The state was in the throes of widespread violence on Monday that allegedly left several BJP workers dead and injured in clashes, and shops being looted, prompting the Centre to seek a factual report from the government on incidents of attack on opposition workers.

"PM called and expressed his serious anguish and concern at the alarmingly worrisome law & order situation @MamataOfficial. I share grave concerns @PMOIndia given that violence vandalism, arson, loot and killings continue unabated," Dhankhar wrote on Twitter.

Four people were killed in alleged clashes between TMC and BJP supporters in Burdwan district on Sunday and Monday, officials said. The TMC claimed three of them were its supporters.

Videos of alleged arson at a BJP office with bamboo poles and roof tiles burning amid worried cries of people running away from the premises were shared by the party.

"Police @WBPolice @CPKolkata must end senseless political violence, vandalism, arson, killings and intimidation that shames democracy. Why post poll violence only WB? Why this assault on democracy?" the governor asked on the microblogging site.

"Reports indicate horrendous state of affairs.

Horrified people are fleeing to save themselves," he added.