"Yechury has being detained at Srinagar airport and not allowed to move anywhere. This despite the fact that he had informed the administration about his visit to meet Tarigami who is not well and other party workers," the Communist Party of India-Marxist (CPI-M) tweeted.
"We strongly protest this illegal detention," the party added.
Earlier in the day, before leaving for Srinagar, Communist Party of India-Marxist General Secretary Yechury took to Twitter to announce his plans to go to Kashmir: "D. Raja and I are on our way to Srinagar on the 9.55 a.m. Indigo flight to meet Tarigami and our other comrades in Jammu and Kashmir."
The CPI-M leader attached the picture of the letter he wrote to Governor Satya Pal Malik on Thursday seeking permission to meet his party leaders.
In his letter to Malik, Yechury said: "The CPI-M has an active unit in Jammu and Kashmir and it has a MLA, Mohd Yusuf Tarigami, in the dissolved J&K Assembly.
"As the General Secretary of a national party, I wish to visit Tarigami (who I was informed is not keeping good health) and other members of my party. I propose to reach Srinagar on the 9th (August) morning to meet them.
"I hope the administration will not create any hurdles in discharging my responsibilities as a leader of my party," Yechury said.
The Left parties have protested the revocation of Article 370 that gave special status to Jammu and Kashmir.
On Thursday, Congress leader and former Jammu and Kashmir Chief Minister Ghulam Nabi Azad was not allowed to enter Srinagar and was sent back to Delhi.
Azad had gone to Srinagar to meet party leaders and assess the situation following the BJP government's decision to abrogate Article 370 of the Constitution which gave special status to Jammu and Kashmir and bifurcate the state.
Jammu and Kashmir, which has been converted into a Union Territory, is under lockdown since the past five days to prevent any protests over the government revoking the special status to Jammu and Kashmir.
( With inputs from IANS )