Drug bust in Shanghai, China, nets 2.4 tons of meth

A police officer stands guard to maintain traffic safety at the site of the New Year's Eve stampede in Shanghai Jan. 3, 2015.

Wang Zhao/AFP/Getty Images

BEIJING -- Chinese police seized 2.4 tons of methamphetamine in one of the country's largest drug busts, authorities in the eastern city of Shanghai said Thursday.

Twenty-eight people were arrested in the joint operation with police from the southern province of Guangdong, where the drug lab was discovered, Shanghai police said in a statement on their official microblog.

They said the hunt began with the discovery of a drug dealer in August and that evidence led police to the lab in Guangdong.

Illegal drugs remain a major problem in China despite tough laws, including the death penalty for offenders.

Last year, Guangdong police used 3,000 armed police officers in a drug sweep that seized nearly 3 tons of methamphetamine and 23 tons of raw materials to manufacture the stimulant drug.