Investigation has revealed that the woman, apparently his mother, had hired an autorickshaw to Nedungulam from the bus stand and asked its driver to stop at the spot and wait till she returned. Later, she travelled in the same vehicle to another place.
Residents of Nedungalam, who noticed the woman throwing the bag, opened it after they heard the cries of the infant.
They also stopped the autorickshaw driver who was coming back after dropping the woman and handed him over to the police along with the infant.
The baby was admitted to a government hospital here and his condition was stable, police said, adding that based on information provided by the driver, a search was on to trace the woman.