Armed police are intensifying the crackdown on the cross-border flow of narcotics. Zhang Yi reports from Mangshi, Yunnan province.

One of the biggest hits at the Chinese box office during the recent National Day holidays was Operation Mekong, an action-thriller by Hong Kong director Dante Lam, which depicts the hunt for a drug lord in the wilds of the Golden Triangle, Asia's largest opium-producing area that straddles Myanmar, Laos and Thailand.

The public may have been gripped by the movie, but according to Meng Liming, it was light relief