PETALING JAYA (THE STAR/ASIA NEWS NETWORK/AFP) - Hong Kong student activist Joshua Wong was barred from entering Malaysia at Penang Airport on Tuesday.

The 18-year-old student leader is said to have been scheduled to speak at forums in Penang, Ipoh, Johor and Petaling Jaya on June 3, the eve of the 26th anniversary of Tiananmen Square Massacre.

"This morning we stopped Hong Kong activist Joshua Wong from entering Penang. We subsequently deported him back to Hong Kong on the same Dragonair flight,” said an immigration official at Penang airport, on condition of anonymity. The official declined to say why Wong was denied entry.“Malaysian government is not letting me enter their border. Taking my original flight back to Hong Kong,” Wong had said earlier on his Twitter account.In a separate Tweet, he added that a Malaysian customs officer had said the refusal was due to a “government order”. Wong did not elaborate.He was due to arrive back in Hong Kong in the late afternoon.Scholarism, the student protest group which Wong founded, posted a statement on its Facebook page saying he had been invited to visit by “Malaysian activists”.“Local personnel temporarily took away his passport for inspection when he arrived... and later refused his entry and asked him to be returned to Hong Kong with no reason,” it said.Wong said he had been invited to share his “experience and views on the Umbrella Movement and the June 4 incident", the South China Morning Post reported.A spokesman for Hong Kong’s immigration department said the entry of its residents to other countries was “out of the control of the Hong Kong government”.Hong Kong authorities have not imposed any travel restrictions on Wong.

"Malaysia... explain why he is sent back to Hong Kong? Afraid of more street protests," tweeted Bersih 2.0 chairman Maria Chin Abdullah.

"Our government must grow up, don't be small minded - Joshua Wong is a pro-democracy activist. Is that a crime to bar him from entering Malaysia," questioned civil liberties lawyer Eric Paulsen on Twitter.

"Joshua Wong, 18, too dangerous to step foot in Malaysia? Strange and embarrassing," tweeted human rights lawyer Michelle Yesudas.

Wong has become the face of Hong Kong's pro-democracy student protest movement, leading students in a massive protest last year.

He was later charged on November last year with obstructing a bailiff clearing one of Hong Kong's three protest areas.

He was also banned from a large part of Mong Kok, an area in the Yau Tsim Mong District in Hong Kong.

In December 2014, he and two other students began a hunger strike and demanded the Hong Kong government restart dialogues on electoral reform.

Four days into the strike, he decided to end it due to "strong urging from the doctor".

Wong was arrested once again in January for questioning over his involvement in civil disobedience offences over the pro-democracy demonstrations.

His visit came less than two weeks before the 26th anniversary on June 4 of the Tiananmen Square massacre of pro-democracy protesters in Beijing.Hong Kong commemorates the anniversary each year with a candlelit vigil attended by thousands in Victoria Park.