Communist Party of India-Marxist general secretary Sitaram Yechury and Communist Party of India chief D Raja were not allowed to enter Jammu and Kashmir on Friday and were sent back from Srinagar airport after a brief detention, party sources said.
The Left leaders had gone to Srinagar to meet CPI-M leader Md Tarigami and other party colleagues.
"They showed us a legal order which did not allow any entry into Srinagar. It stated that even escorted movement int the city was not permitted due to security reasons. We are still trying to negotiate with them," Yechury said.
Later, party sources said they have been sent back to Delhi.
Yechury and CPI general secretary Raja had written to Jammu and Kashmir governor Satya Pal Malik on Thursday informing him of their visit and requesting him to facilitate their entry.
"Both of us had written to the J&K governor requesting him that there should be no hurdles for our visit... despite that we have been detained. I wanted to meet my ailing colleague and our comrades who are here," Yechury said.
In a statement issued by the CPI-M politburo, the party hit out at the government over the detention, saying it was an "anti-democratic" act, which showed the ruling BJP's "authoritarian face".
"The politburo calls upon the people to protest this anti-democratic act of the BJP government," the statement said.
The CPI in its statements said that detention was "despicable".
"PM Narendra Modi yesterday in his broadcast to the nation claimed that there is normalcy in Jammu and Kashmir and people are happy with the decision of abolition of article 370 and 35A.
"If it is true then why national leaders are not allowed meeting people of Jammu and Kashmir. The whole Jammu & Kashmir is under seize with tens of thousands of security forces and they are parading in the streets of towns, villages and undemocratic curfew is in existence. This reflects the reality," the party said in a statement.
On Thursday, Congress leader Ghulam Nabi Azad was detained and sent back to Delhi from the Srinagar airport.