Hours after Trinamool Congress (TMC) leaders were detained for staging a dharna outside the Election Commission here, party leader and MP Derek O'Brien said they will continue their protest at the Mandir Marg police station.

A 10-member delegation of the TMC had announced the dharna after meeting a full-bench of the poll panel to demand that the chiefs of the Enforcement Directorate (ED), the Central Bureau of Investigation (CBI), the National Investigation Agency (NIA) and the Income Tax (I-T) Department be changed.

The Mamata Banerjee-led party has been alleging that the central probe agencies have been targeting opposition parties ahead of the Lok Sabha polls at the behest of the BJP, which is in power at the Centre.

"Our 24-hour dharna will continue inside the police station or outside. We will carry on," O'Brien told reporters from behind the gates of the Mandir Marg police station, around 2.5 km from the Election Commission (EC) office on Ashoka Road in Central Delhi. .

Besides O'Brien, TMC MPs Mohammed Nadimul Haque, Dola Sen, Saket Gokhale and Sagarika Ghose, MLA Vivek Gupta, former MPs Arpita Ghosh, Santanu Sen and Abir Ranjan Biswas, and party's students' wing West Bengal vice president Sudip Raha were detained. "We were supposed to have our protest outside the EC. But now we are here (police station)," O'Brien said.

On their detention, a senior police officer said the action was taken as section 144 of the Code of Criminal Procedure -- that prohibits large gatherings -- is imposed in the area around the EC office and no permission was taken for the protest.

O'Brien claimed that after being detained, they were driven around the city, before being brought to the police station.

"They drove us around Delhi for about one and half hours... after we protested, they brought us to the Mandir Marg police station," he said.

In a letter to the EC, the TMC alleged that BJP leader Jitendra Tiwari met NIA Superintendent of Police DR Singh on March 26 allegedly with a "packet", and left the flat empty handed after around an hour long meeting.

"The sequence of events are ample evidence of the unholy nexus and agreement between the BJP and the NIA to harass AITC's workers so as to ensure that they are diverted from performing their electioneering duties," the TMC said in its letter to the EC.

The party has alleged that during this meeting, the BJP leader handed over a list of TMC leaders and workers to be targeted.

"This is complete murder of democracy. Abhishek Banerjee, our national general secretary along with my fellow MPs and ministers have asked for an appointment with the West Bengal governor tonight," O'Brien said.

"We are here to fight. So we will carry on our peaceful dharna. This is the situation," he said.

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