Two people are said to have died after being bitten by the non-native spiders, which are reported to have attacked scores of Sadiya residents.
“We cannot say for sure that the fatalities were due to the venom; it could have been because of allergic reaction to the venom,” Dr. L. R. Saikia told The Times of India.
He says the two victims had sought treatment from area witch doctors, who cut their wounds with razors, drained out the blood and burned it. This could have possibly caused a fatal infection.
Regional zoologists have yet to determine what type of spiders they are, but believe they could be tarantulas or even an entirely new species.
Saikia said those who were bitten were attacked after they tried to shoo off the arachnid, which leapt at them and firmly buried in its fangs.
Villagers are reportedly now keeping their lights on at night and standing guard against spiders entering their mud-and-thatch huts.
Jintu Gogoi was one of those bitten by the spider. He told the daily how he suffered excruciating pain and nausea after being attacked, with his finger still blackened and swollen weeks later.
Dr. Anil Phatowali, superintendent of the town's hospital, said victims had not been administered antivenin since no one was sure the spiders were actually venomous.