BEIJING, Feb. 20 (Xinhua) -- China's top copyright watchdog has pledged to strengthen the crackdown on bootlegging of films in theaters and strictly inspect online platforms that sell or spread pirated works, the China Daily reported on Wednesday.

Inspections will focus on websites, smartphone applications, WeChat accounts and e-commerce platforms, the National Copyright Administration said early this week.

Serious piracy cases will be transferred to police departments to be dealt with as criminal matters, it said.

Several popular movies shown in cinemas, including "The Wandering Earth" that is now ranked second in China's all-time box office, were found to have been pirated during the week-long Spring Festival holiday that ended on Feb. 10.

Movie piracy remains a serious problem that is hard to solve, as "many pirated movies are put on websites that used overseas servers," Chen Yongwei, an intellectual property professional at Peking University, told the newspaper.

The copyright administration said that it was aware of overseas servers and would increase international law enforcement cooperation with other countries and regions this year.

It deleted some 7,700 links to pirated movies during the Spring Festival holiday.

The copyright watchdog said it would join hands with the State Film Administration, the Ministry of Public Security and the Ministry of Industry and Information Technology to ramp up the fight against film piracy.