Communist Party of India (Marxist) General Secretary Sitaram Yechury and Communist Party of India leader D Raja were sent back to Delhi on Friday after being detained at Srinagar airport, PTI reported.

“They showed us a legal order which did not allow any entry into Srinagar,” the CPI(M) told PTI over phone after he was detained. “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 their detention at the airport was a violation of their democratic rights. “We strongly protest this suppression of basic freedoms by the Centre and stand in solidarity with the people of Kashmir,” Yechury said in a tweet.

“Since Sunday, we do not know the whereabouts or of the well-being of Com Yusuf Tarigami and our other comrades,” Yechury wrote in another tweet. “As we were detained at the airport, we have left a note for Com Tarigami. We will explore all legal options to trace him.”

The CPI(M) had earlier tweeted that Yechury was not being allowed to move anywhere even though he had informed the local administration about his planned visit to meet party workers and a former legislator of his party who was unwell. “We strongly protest this illegal detention,” the party said.

On Thursday, both Yechury and Raja had written separate letters to Jammu and Kashmir Governor Satya Pal Malik to inform him of their planned visit to the state. In similarly-worded letters, they had expressed hope that they would not face hurdles during their visit. Yechury had said he was going to visit Kashmir to meet members of his party. D Raja of the Communist Party of India had also told Malik that he wanted to meet his party members.

Congress leader and former Chief Minister Ghulam Nabi Azad was on Thursday not allowed to exit the Srinagar airport and was sent back to Delhi. Azad had arrived in the city to meet Congress workers as the state was still under a tight security and information clampdown since Sunday night. Restrictions were eased on Friday.

This week, the Union government decided to revise Article 370 of the Indian Constitution, which gave special status to Jammu and Kashmir, to a single clause revoking the state’s privileges and ordering all laws to be applicable in the region the way they are in the rest of India. The government also split the state into two Union territories, making Ladakh a separate territory.