JOHOR BARU, Sept. 14 -- The air quality in northern and central parts of Johor took a sharp hit today, forcing the authorities to close 211 schools in Muar and Tangkak, after the Air Pollutant Index (API) recorded very unhealthy levels.

More than 64,000 primary and secondary school students are affected by the closure tomorrow as Johor observes Sunday as the first day of the week, where Fridays and Saturdays are official weekends.

Johor Education Department director Azman Adnan said the Education Ministry has stated that if the API reading was more than 200, then all schools in the area or district should be closed immediately.

"Based on today's API readings, which recorded an increase, the school session in the two districts will be c...