Sikkim police on Saturday arrested six persons for allegedly assaulting K.N. Rai, the former Speaker of Sikkim Assembly and a senior Sikkim Democratic Front leader.

Rai, 62, was flown to Delhi for treatment on Saturday evening.

The police have not disclosed the political affiliations of the accused.

The political atmosphere heated up in Sikkim in a poll-bound year following the attack on Rai at Maji Goan, Melli, some 56km east of Gangtok near the Sikkim-Bengal border on Friday afternoon. The SDF alleged the role of the ruling Sikkim Krantikari Morcha (SKM) activists.

A senior police officer said the six were arrested from three different areas of Melli.

"Three police teams were formed. We cordoned off jungle areas and started a combing operation,” the officer said.

The officer said while accused Jiten Rai, Laxman Rai and David Rai were arrested from Kubeda jungle at around 10.30pm on Friday night, another team arrested Awan Tamang from Melli Gumpa area around 2am on Saturday.

"We arrested Karan Tamang and Saroj Thapa around 6am from Tribeni jungle area,” said the officer

The police have not disclosed the political affiliation of the six accused aged between 20 and 30 years.

Pawan Chamling, the SDF president and former Sikkim chief minister, visited Rai at a Siliguri hospital on Saturday and termed the attack “pre-planned”.

"He (Rai) was attending a social and not a political event (at Melli). It was pre-planned.... Sikkim was a peaceful state earlier but it is now just the opposite. People are not safe,” said Chamling.

Hospital sources said Rai had suffered a fracture on the upper portion of the jaw. The medical bulletin of the hospital states Rai is a patient of myelofibrosis (bone marrow cancer).

Later on Saturday, Rai was flown to Delhi, hospital sources said.

The attack on Rai was widely condemned.

SDF supporters held a protest in Melli on Saturday. The ruling SKM also condemned the assault.

“I strongly condemn the unpleasant and anti-social act of assault on former Speaker Shir KN Rai in Malli, Namchi district today. Shri KN Rai, a respected politician and senior citizen, should never have been subjected to such mistreatment,” chief minister P.S. Tamang (Golay) wrote in his verified Facebook account soon after the attack.

He promised "strong actions against the perpetrators". Sikkim thrives on peace and harmony and such despicable acts will not be tolerated, he said.

"I urge everyone to uphold peace, unity, and tranquility, rejecting violence and strife,” the Sikkim chief minister added.