A Hong Kong-based NGO on Sunday called for a ban against any person or group that promotes "Hong Kong independence" or opposes the regional government's policies in schools, in a bid to prevent the spread of wrong ideas which would undermine the region.

The Hong Kong Academy of School Managers, established in 2015 and composed of Hong Kong school managers at all levels, published a statement on its official website which says it has recently found some people from the educational field who instigated or organized teams in schools to challenge the regional government system and promote "Hong Kong independence."

The statement said some members claimed they want to encourage students to discuss social issues and that schools should not restrict them from expressing their views.

However, they intend to "plant the seeds of separating China and opposing the Basic Law at schools," and the academy firmly opposes such acts, read the statement.

An official publication of Hong Kong University Students' Union, Undergrade, continued to promote "Hong Kong independence" and called for an "effective and continuing" fight against the Chinese mainland, Hong Kong-based Takungpao reported.

The journal once published a cover story in February 2014, calling for Hong Kong self-determination and issued a special edition on Hong Kong democracy and independence in September, in which an article compares Hong Kong to Singapore and estimates the number of conscripts and arms it can gather.

Hong Kong Chief Executive Leung Chun-ying said in his third policy address in January 2015 that residents should remain vigilant to calls for independence, and he singled out Undergrade.

A commentary published in Ming Pao on Thursday said that some "Hong Kong independence" organizations have penetrated middle schools, which reminded people of the Middle East, where youths were recruited and sent to the battlefield.

The academy's statement also called for all school managers to take precautions and require educational authorities to strictly deal with those who violate regulations to prevent the wrong ideas from being spread at schools which undermine Hong Kong.