A court in northeast China has convicted four "monkey busking trick" performers, arousing nationwide concern about the protection of intangible cultural heritages, the Beijing Morning Post reported.

The traveling buskers were picked up in Mudanjiang city, Heilongjiang province, while performing with six trained monkeys in July. Police said the buskers lacked wild animal transportation certifications.

Two months later, they were convicted of "illegally transporting rare wild animals" by a local court.

The buskers are from Henan province's Xinye county, birthplace of the tradition of "monkey busking tricks." The street performance dates back to the Eastern Han Dynasty (25 AD - 220 AD) and was listed as a national intangible cultural heritage in 2008 by the State Council.

The incident has triggered doubts over how such a tradition could be considered a crime.

This intangible cultural heritage needs space to survive, according to the newspaper, adding that only four or five hundred performers remain.

But others said the traditional way of performing did not preserve and protect the intangible cultural heritage, citing frequent reports of performers abusing monkeys.