Twenty-six railway tunnel workers in northwest China's Inner Mongolia Autonomous Region have been sickened by food poisoning, a spokesman with the regional safety inspection bureau said Wednesday.

None of the victims' lives was in danger, said the spokesman.

All 26 workers in a team working in a railway tunnel, in Zhuozi County of Ulanqab City, about 150 km from the regional capital Hohhot, fell sick soon after finishing lunch around 11 a.m. Tuesday.

The cook of the poisoned food, who asked to remain anonymous, said some workers fainted while others had headaches and started to vomit after they finished the Chinese cabbage soup she cooked. The woman also suffered from the food poisoning. One of the workers then called the ambulance, she said.

A preliminary investigation showed all workers were poisoned by organophosphor, which is often used in pesticide, said the spokesman.

The tunnel is part of a railway being built to link Ulanqab City's Jining District and Baotou City, also in Inner Mongolia.

Investigation into the food poisoning is still under way.