Here are the latest developments:
About 70 women protesters from the Socialist Unity Centre of India were dragged across the road by policewomen and put into buses when they resisted being removed from the Dharamtala area in Kolkata, where they had blocked traffic.
Trinamool workers clashed with those of the CPM at Behrampore in Murshidabad district, where a former MP and a sitting lawmaker of the CPM were injured. Waving party flags, Trinamool supporters also attacked a CPM office in Birbhum district.
Clashes were reported from many other places. In Siliguri, mayor and senior CPM leader Ashok Bhattacharya was arrested for leading a protest.
With Mamata Banerjee telegraphing zero tolerance for strikes, her government and party, the Trinamool Congress, tried hard to ensure minimum impact. But the opposition Left declared the strike a resounding success in Bengal.
Ms Banerjee disagreed, saying her state registered high attendance at work today. "Industry strike was a failure; our people worked. Usual attendance is 91. Today Kolkata had 93 per cent attendance and 97 per cent in districts," she asserted.
She also emphasised, "We are against bandhs...the bandh culture should be broken. These are not spontaneous protests," and attacked the Left, which supports a number of the trade unions that called today's strike.
Biman Bose of the CPI alleged police excesses against protesters and Left leaders in many parts of the state and told NDTV, "The Chief Minister's voice and that of Prime Minister Narendra Modi are the same in respect of tackling hartals (strikes)."
In Kolkata, most schools were closed, government colleges were open but almost no attendance. Buses and the city's metro operated as usual, but few commuters ventured out, though government offices recorded a good attendance.
Flights operated normally at the NSC Bose International Airport, though passengers complained that it was difficult to find transport out of the airport.
The unions are protesting against new labour reforms planned by the government and also demand that the government dump plans to sell off stake in state-run companies to boost the public purse and to shut down unproductive factories.