Before embarking on statewide tour, Kanhaiya detained briefly in Bihar

There was heavy deployment of police when Kumar arrived at the Bhitiharwa Ashram, set up by Mahatma Gandhi, at around 10 am as per schedule, along with hundreds of supporters.

The former JNU student leader was allowed to enter the premises, garland a statue of Gandhi and take part in singing of devotional songs on the occasion of his death anniversary.

"When we were about to leave for the venue of the rally in Bettiah, an official came forward to inform that he was the sub-divisional magistrate and we were being detained since permission for our rally was cancelled. He, however, did not produce any official communication in this regard," Kumar told PTI over phone.

As his supporters grew agitated, Kumar urged them to stay calm and send across the message that they are law-abiding people. He delivered a brief speech, video footage of which was shared on social media and which he signed off in his typical style, with rendition of "azadi" verses.

Kumar was let off after a couple of hours and he subsequently left for Motihari, the headquarters of adjoining East Champaran district to address another rally.

Officials in West Champaran remained tight-lipped over the development though sources in the local administration said on condition of anonymity that the measure was taken in view of the district being "communally sensitive".

"The permission for rally at Bettiah was cancelled without any valid reason. We were detained and let off after the local administration received instructions from higher authorities," Kumar said.

"There was simply nothing in our programme that the administration could have taken exception to. The rally was being held not under the banner of any political party. It was not aimed at any electoral gains," Kumar, who made his electoral debut as the CPI candidate from Begusarai Lok Sabha seat last year but lost to BJP's Giriraj Singh, said.

"Of course, our objective is political, in as much as we are opposed to this divisive legislation which is nothing but a diversionary tactic on part of the ruling dispensation to deviate the national discourse from real issues – unemployment, poverty and inadequate education and health care facilities," the 32-year-old Leftist leader said.

"But we are not being political in a narrow sense. It is not for nothing that we were let off after strings were pulled by Congress MLA Shakeel Ahmed Khan whose party is not an alliance partner of the outfit to which I belong," Kumar pointed out.

At the rally in Motihari, he deplored the firing incident at Jamia Milia Islamia and launched a veiled attack on the BJP-RSS, saying "people are invoking the name of Lord Ram to convert the country into the land of Nathuram (Godse)".

Kumar has embarked on a statewide 'Jan Gan Man Yatra', which would conclude with a rally on the theme 'naagarikta bachao, desh bachao' (save citizenship, save the country) in Patna on February 29.