Haze in Singapore on September 12 (Photo: straitstimes.com)

This is the first time in the recent three years that the air quality of the country has fallen below the safety level.

The National Environment Agency (NEA) of Singapore on September 14 reported that the air quality in the country was worsening and the Pollutant Standards Index (PSI) in the country in late afternoon reached 108. Meanwhile, the index will be regarded as unhealthy if it reaches from 100, and people are advised to minimise outdoor activities.

The NEA warned that the situation will last for the next few days, giving a number of preventive measures for locals such as wearing masks when going outside.

Haze in the 5.6 million-strong country may affect the Formula 1 race which is slated for September 20-22.

In 2015, the PSI reading in Singapore once surpassed 300, forcing the government to order the close of schools.

Indonesia is experiencing the worst forest fire in the recent two decades, affecting many Southeast Asian countries such as Singapore, Malaysia and Thailand. Haze has forced hundreds of schools in Serawak province of Malaysia to close./.VNA