'Very unhealthy' air quality recorded in the two towns as Fire and Rescue Department battles more bush fires.
Other towns in Sarawak have 'moderate' air quality.
The Air Pollutant Index reading for Miri drops from 'hazardous' to 'very unhealthy'.
Most parts of the country record 'moderate' to 'good' API readings.
'Unhealthy' readings at Samarahan and SK Kuala Baram 2, Sarawak, and Johan Setia, Selangor.
Frequent rainfall is expected between the third week of September and October.
Air quality at another 67 areas reported to be at moderate levels Wednesday.
The president notes complaints about haze are once again making headlines in neighbouring countries.
The air quality in Indera Mahkota, Pahang, hits 'unhealthy' level as peat fires in Pekan worsen the situation.
Environment ministry officials will bring up the haze problem at a two-day meeting in Brunei.
There are worries that the haze this year will be worse than the one which followed the devastating fires in 2015.
Smog from Indonesia drifts over western Peninsula and Sarawak, causing hazy skies.
As bush fires threaten 150 hectares of forest in Miri, deputy chief minister urges all agencies to be on full alert.
Another 66 areas had moderate to severe haze Friday, according to the Malaysian Air Pollution Index.
The burning of the forests and plantations for agriculture, in addition to open burning, have become a familiar Indonesian trait during the mid-year period.
This has been blamed on the forest fires in 6 Indonesian provinces.
The smog, which appears to be coming from a nearby factory, has caused breathing difficulties among students, says PIBG chairman Christina Lai.
New policies include educating and training communities in fire prevention and setting up a Peatland Restoration Agency.
SAM says the situation on the ground appears at odds with API readings by the DoE showing moderate numbers.
EcoCart currently works with three major e-commerce websites, helping consumers and retailers to do their part for the environment.
According to the World Health Organisation (WHO), majority of Asians live in a polluted world which puts them at a greater risk of falling sick.
Authorities have seeded clouds to provoke rain, sprayed overpasses with water to catch micro-pollutants, and even urged people not to burn incense ahead of Chinese New Year.
The air quality index, or AQI, reached 170, the seventh worst urban reading globally according to AirVisual.
More enduring measures are needed, especially if the culprits involved are Malaysian companies.