India's food safety regulator has ordered state governments to check all noodle products made in the country after high lead levels were found in Nestle India's noodles. Several Indian states, including the city government of the capital Delhi, have already halted the sale of Nestle's Maggi noodles after tests showed the hugely popular snack was unfit for consumption. The state of Tamil Nadu became the first state to ban other noodle brands as well. "I have told states to not confine only to Maggi, but extend to other manufacturers of noodles," Yudhvir Singh Malik, chief executive of the Food Safety and Standards Authority of India (FSSAI), told Reuters. "Why should we isolate Nestle? It's not a question of targeting." Several companies including ITC, Hindustan Unilever, Reliance Industries, as well as numerous smaller firms sell noodle products in India. The national checks were triggered after routine tests in northern Uttar Pradesh state showed lead content of 17.2 parts per million in Nestle's instant noodles - seven times the legal limit. Nestle has challenged the findings. Tamil Nadu said it would extend its ban to other noodle brands after tests found excess lead in products sold by Nestle, Reliance and domestic firm CG Foods. "Manufacturing, stocking and sales ... will be banned for three months as an initial move," the state government said in a statement, adding that companies will immediately need to withdraw all stock in the market. Uttarakhand has banned Maggi noodles for 90 days, while Delhi on Wednesday slapped a 15-day ban. The states of Gujarat and Jammu & Kashmir have also banned sales of Maggi. Some other states have, meanwhile, given Nestle's products a clean bill of health, creating confusion among consumers about whether it is safe to eat a brand that accounts for a fifth of its local revenues. FSSAI's Malik, however, said there was no immediate plan to impose a nationwide ban as test reports are still awaited from several states. More results are expected by Monday. In an advisory on May 25, the FSSAI asked all states to run checks on samples of Maggi noodles and submit results by June 1. But only a few states have so far responded. Three state reports were sent back because they did not properly quantify the test findings, Malik said. In one case, a state did not know about the permissible level of lead in noodle products. Malik urged states to form a 12-month plan and improve their surveillance mechanisms: "We do feel concerned (for states) and we have been organizing trainings," he said. "There is a need to strengthen the food testing infrastructure."