KUALA LUMPUR, Oct 21 — Schools in eight states and two federal territories in Malaysia will be closed tomorrow as the Air Pollution Index (API) in some districts hit “very unhealthy” levels, the Education Ministry said today.

This will be the fourth day this week that schools have to be closed due to the annual haze problem.

The ministry said the closure will affect 2,696,110 students in 4,778 schools.

The schools that have to be closed tomorrow due to “unhealthy” API readings are those in Negri Sembilan, Selangor, Putrajaya, Kuala Lumpur, Perak, Penang, Kedah, Perlis, Pahang’s Bentong district, the districts of Kuching, Samarahan, Sri Aman and Betong in Sarawak, the ministry said.

The ministry did not specify which areas recorded a “very unhealthy” API reading.

Yesterday, the ministry said 2,528 schools — involving 1,734,668 students — in four states and two federal territories will be closed for today.

On Tuesday, 3,029 schools and 1,909,842 students were affected in the school closures.

According to the API scale used by Malaysia, readings below 50 indicate low pollution, 51-100 is considered a moderate range, 101-200 is unhealthy, 201-300 is very unhealthy, while readings above 300 is considered hazardous.