They were searching for the head of the party Bimal Gurung, who has been on the run since government prosecutors brought terrorism charges against him over a 104-day protest that crippled the region and left almost a dozen people dead.
West Bengal police on Friday said Gorkha Janmukti Morcha supremo Bimal Gurung has links with Maoists and insurgent groups in the Northeast and had procured sophisticated arms from them.
In connection to the attack on the police in Darjeeling last night, ADG Anuj Sharma said that they had received a tip-off that Bimal Gurung was planning to sneak into Darjeeling from the neighbouring state of Sikkim.
The CNN News18 report noted that firing between the police and GJM supporters is still going on, which might have helped Gurung escape.
A number of police vehicles were also set ablaze during the clashes. During the clashes, several policemen, including a sub-inspector were injured and 2 are reported to be dead.
Supreme Court says human rights of Rohingya refugees can not be ignored
It further rapped the government saying that there is a need to strike a balance between human rights and national security. The court also observed that no Rohingya refugees should be deported until the next date of hearing in the case.
Following the incident, a very heavy police force along with Central paramilitary forces were deployed to the scene, a police official said.
"The police recovered six AK-47 rifles, 1 9mm pistol, ammunition, bombs and bomb making material from the hideout", he added.
After an appeal of Union home minister Rajnath Singh on Tuesday, the Gorkha Janmukti Morcha (GJM), finally called off an indefinite strike in Darjeeling after 104 days on September 27.
The latest protests severely affected production of Darjeeling tea, regarded as some of the world's finest, as workers failed to turn out for the harvest.
The indefinite strike was called with the demand of a separate Gorkhaland. There is a virtual split in the GJM with Binay Tamang leading a faction that is backed by the state government.