Delhi ’s government imposed the most stringent set of restrictions on the movement of vehicles and people as the toxic smog enveloping the Indian capital worsened on Monday. The city’s average air quality index was 457 in the morning, beyond the “severe plus” category, according to government data.

In several areas of the city, pollution levels were more than 50 times higher than the World Health Organization’s recommended safe limit. Forecasts say the poor air quality will continue into the week.

Authorities in India’s capital have shut schools, halted construction and banned non-essential trucks from entering the city after air pollution shot up to its worst level this season