"The gas leakage was reported between phase I and II of Vatva GIDC (Gujarat Industrial Development Corporation) area in the city tonight," a senior fire official said from the site.
"The primary assessment of the gas indicates that it is ammonia," he said, adding that the fire brigade team was searching for the source of the leakage.
A man named Natwar Parmar (45), and another person who has not been identified yet, were affected by the leakage and were taken to the nearby L G Hospital for treatment, an official from '108' emergency service said.
Vehicular movement towards Vatva over-bridge has been stopped for safety, Police Inspector in Vatva H J Chaudhary said.
At least 10 fire vehicles with a large contingent of fire officials are at the site to control the situation, they said.