A German television crew was attacked by workers while filming a documentary on pollution near a Chinese chemical factory earlier this week.

The four-person TV team had to be rescued by armed police after they were trapped for nine hours by workers at the Do-Fluoride plant near Jiaozuo in Zhongzhan county, in Henan province.

German broadcaster ARD claimed the irate Chinese workers shouted "kill the foreign spies" and also seized their cameras and video tape.

"Factory officials appeared to have misinformed workers and agitated against us,” the Germans said in a statement.

"We were considered spies who had tried to gather intelligence regarding Do-Flouride's technology."

A similar incident occurred last month when a reporter for Japan's Asahi Shimbun newspaper was beaten while covering an environmental protest in Nantong, Jiangsu province. The reporter, Atsushi Okudera, was attacked while attempting to take photos of demonstrators being beaten by police.

Up to 20 police harassed him and seized his camera and never returned it.