Two Chinese activists said on Thursday they had been barred from travelling to India after being denied visa. While activists told India Today they believed "Chinese pressure" was a factor behind the cancellations, the Indian government said they had applied for the wrong category of visa.

The activists were due to attend a high-profile meeting of Chinese dissidents and exiles in Dharamsala on April 28. Earlier this week, a Uyghur exile, Dolkun Isa, who was scheduled to speak at the same meeting, said his electronic tourist visa was revoked.

The Ministry of External Affairs on Thursday said of Isa's case that he had applied for the wrong category of visa. A conference visa is required for those attending meetings, while electronic tourist visa is allowed only for tourism and "casual" business meetings. The MEA said information about the conference "was suppressed in the visa form and that the tourist visa does not permit".

On Tuesday, Lu Jinghua, a well-known Tiananmen activist and former 1989 protest leader, and Hong Kong activist Ray Wong, both said their electronic visas had been denied. Lu said she was about to board an Air India flight from New York when she was told her visa had been denied.

"At the airport, the Air India staff told me simply that I couldn't board as my visa was cancelled," she told Mail Today from New York.

While Lu suggested that "Chinese pressure on the Indian government" was to blame, officials said as in Isa's case, Lu and Wong had also applied for a wrong tourist visa despite travelling for a meeting. The officials explained that electronic tourist visa is issued automatically, but can be cancelled if applications are found to suppress information.

The MEA said it "would caution against meanings being read, either on visa being given to Mr Isa or its subsequent cancellation".

But despite the Indian government's explanation, the cancellations had sent a ripple through the community of Chinese dissidents and exiles, said activist and former Tiananmen leader Rose Tang, who has in the past travelled to India. Sources in Dharamsala said it had been common for participants to travel to India in the past on tourist visa because of the difficulty of obtaining a conference visa which requires MHA clearance, adding that the clampdown was new.

"I am very concerned by the denial of the visa to Jinghua", said Tang. "Now countries like Thailand, Vietnam have already became unsafe for Chinese dissidents. I am worried that India is becoming one more country not on the list of countries I can travel to."

On Isa's case, the MEA said it had also come to its attention that an Interpol Red Corner Notice had been issued in Isa's name. This is thought to have been done at China's behest, as Beijing regards him as a "terrorist" responsible for bombings carried out in his native Xinjiang in the 1990s. Isa denies the charges, pointing out he has been awarded in the west for his human rights activism and has been a German citizen since 2006.