Malaysian authorities have denied entry to a radical Hong Kong lawmaker at Kuala Lumpur's airport, the second time this week they have barred one of the city's outspoken pro-democracy activists.

Leung Kwok-hung said on his Facebook page that he was stopped Friday by authorities and put on a flight back to Hong Kong.

It said his passport was taken away and he was questioned about the reason for his visit.

It's not clear why he was prevented from entering.

On Tuesday, 18-year-old Joshua Wong was sent back to Hong Kong after flying to the northern city of Penang. Immigration officials said he was on a blacklist.

Wong and Leung were planning to attend a forum marking the anniversary of a 1989 crackdown on pro-democracy protesters in Beijing's Tiananmen Square.