Kuala Lampur, Sept. 18 -- A total of 51 schools in the southwest district of Penang island were ordered to close early this morning as the Air Pollutant Index (API) readings for the district reached 211 as at 8am.

Penang environment committee chairman Phee Boon Poh said the state Education Department issued a directive on the school closure at 7.20am.

Phee said he had informed the state executive council on the latest API readings.

As at 9am, the API readings in Balik Pulau climbed to 218, while other parts of the island had readings of 197 in Minden. The air pollution on the mainland read 149 for Seberang Perai and 144 for Seberang Jaya.

API readings are categorised as good for between 0 and 50, moderate for between 51 and 100, unhea...