A journalist was gunned down on Tuesday by a Tripura State Rifles (TSR) trooper during an altercation in western Tripura, raising political tensions and triggering widespread anger.

TSR Second Battalion Rifleman Nandu Kumar Reang opened fire from his AK-47 assault rifle, killing Sudip Datta Bhowmik, 50, in Bodhjung Nagar, a police official said.

Reang was the bodyguard of Second Battalion Commandant Tapan Debbarma. The slain journalist went to meet Debbarma at the battalion headquarters some 25 km north of here. Police arrested the TSR trooper.

Senior police officials including Inspector General of Police K.V. Sreejesh, Inspector General of Police G.S. Rao and Deputy Inspector General of Police Arindam Nath rushed to the spot.

The body of Bhowmik, a reporter with "Syandan Patrika" and television channel "Vanguard", was brought to the Gobind Ballav Pant Medical College and Hospital here.

It would be kept at the Medical College and Hospital until Wednesday. He is survived by his wife, a government teacher, and two children.

Chief Minister Manik Sarkar strongly condemned the killing and asked the Director General of Police to probe the incident.

Both Bharatiya Janata Party (BJP) and ruling Communist Party of India-Marxist (CPI-M) leaders rushed to the hospital and the residence of the slain journalist.

The BJP called a 12-hour state-wide shutdown on Thursday.

"Chief Minister Manik Sarkar should step down immediately," BJP state President Biplab Kumar Deb told the media.

Various Journalists organisations in the northeast, including the Tripura Working Journalists Association, Tripura Journalists Union (TJU) and the Agartala Press Club, denounced the killing and demanded a high level probe into the incident.

The TJU also demanded the resignation of the Home Minister. The portfolio is held by the Chief Minister.

West Bengal Chief Minister Mamata Banerjee and journalist organisations in Assam and Meghalaya also condemned the killing.

On September 20, a television journalist, Santanu Bhowmik, 28, was killed allegedly by some activists of a party in Mandai, 35 km from here.