Authorities say at least 11 people were injured south of Moorhead when anhydrous ammonia leaked from a tank being pulled by a farmer.

Clay County Sheriff Bill Bergquist said their injuries are not believed to be life-threatening.

The farmer was working a field on the south side of 60th Avenue Sunday evening and was pulling a tank of the chemical when the hitch on the tank broke, Bergquist said.

Some chemical escaped from the tank before the farmer could close a valve to shut off the leak.

Authorities said at least three vehicles drove into the toxic cloud.

Carrie Haug is a spokeswoman for MeritCare Hospital in Fargo, N.D. She says patients complained of symptoms such as a burning feeling in the chest, shortness of breath, and watering and burning eyes.