Three people were arrested in connection with the attack on a parliamentary delegation of the Left and the Congress in Tripura's Sepahijala district, police said on Saturday.
The delegation, comprising Left and Congress MPs, was attacked in Nehalchandranagar, a border village of Bishalgarh subdivision, on Friday when it was visiting areas affected by post-poll violence.
"Three persons have been arrested so far, and steps are being taken to apprehend the others involved in the attack. An FIR has been filed in connection with the incident," a senior police officer told PTI.
Security forces have been deployed in the area, he said, adding that senior officers were overseeing the situation.
"Chief Minister Manik Saha, who is currently in Delhi, spoke to DGP Amitabh Ranjan, and asked him to arrest all the accused persons, irrespective of their political colours," another official said.
The CPI(M) said that the joint team of the Left and the Congress were visiting various violence-hit areas of West Tripura, Sepahijala and Khowai on Friday.
"Once the delegation, comprising CPI(M) MP E Karim and Congress MP Abdul Khaliq and AICC general secretary Ajay Kumar, landed at Nehalchandrangar market, they were attacked by miscreants raising slogans of 'Bharat Mata Ki Jai'. One vehicle was severely damaged, while two more cars were also vandalised," senior CPI(M) leader Rakhal Majumder said.
At least 20 shops were set on fire in the area on Wednesday night.
Police said none of the eight members of the team were injured in the attack, and two-three vehicles with leaders of the Left parties and the Congress on board were vandalised.
The team is expected to stay in the state till March 12 after which it will submit a report, and the issue will be raised in Parliament, CPI MP Binoy Viswam said.
Most of the post-poll violence cases have so far been reported from Sepahijala and Khowai districts.
Chief Minister Manik Saha asked the police to take stern action, maintaining that a group with vested interests was trying to create trouble in the state.
The assembly election results were announced on March 2, and the BJP-IPFT government returned to power in the state for the second consecutive term.
