The haze worsened overnight with many complaining of breathing difficulty and visibility falling to 100m in some areas.

There is also a possibility of the open burning ban in the Klang Valley being extended to Perak and Negri Sembilan.

Malaysians have been advised to only expect a respite from the dry and hazy weather in October when the monsoon season starts.

The southwesterly winds bringing smoke from Sumatra is also expected to change direction then. A substantial improvement in air conditions is also contingent on forest and peat fires locally and in Riau and Sumatra being put out.

At 5pm, visibility in Tanjung Karang was so bad that motorists had to switch on their headlights. Similar situations were reported in Klang and Port Klang.

The situation was not better in many parts of the city and surrounding areas as thick haze hovered around buildings and green lungs.

Visibility was only a kilometre or less in many parts of Selangor, Putrajaya, southern Perak and Seremban at noon.

Police advised motorists to switch on headlights in areas of poor visibility.