The attack on Amarnath pilgrims "signifies the rise of religious extremism" among militants in Jammu and Kashmir, the CPI-M said on Tuesday.
"The people of Kashmir have always viewed the Amarnath shrine as part of its syncretic heritage," the Communist Party of India-Marxist said in a statement.
"The attack on the pilgrims signifies the rise of religious extremism within the ranks of the militants," it said, referring to the Monday attack that left seven pilgrims dead.
"One of the aims of this attack is to deepen the communal divide. It is important that this provocation does not succeed," the party said.
"This can be accomplished by ensuring that peace and communal harmony prevail in Jammu and Kashmir and the rest of the country."
The CPI-M denounced the attack and conveyed its heartfelt condolences to the bereaved families and its sympathies for all those injured.