SANTA TERESA, N.M. — An unknown hazardous material sickened about 200 people Tuesday just northwest of El Paso, as some workers in the industrial area where the substance released described feeling a burning sensation on their skin, according to New Mexico authorities.

A 1-mile area surrounding the Dona Ana County Industrial Park and Mexico border crossing at Santa Teresa was evacuated for a few hours and the county airport was closed. Workers a few miles away said they could smell something.