CHENNAI: Teams from Bureau of Indian Standards (BIS) raided Amazon and Flipkart warehouses in Tamil Nadu Wednesday, seizing thousands of uncertified products, including water bottles, toys, fans, and diapers. At Amazon's Puduvoyal warehouse, officials confiscated 3,376 items worth Rs 36 lakh for lacking BIS certification. Flipkart's Koduvalli warehouse had baby diapers, casseroles, and steel bottles without statutory marks.