Singapore: Pollution from forest fires in Indonesia pushed Singapore's air quality to unhealthy levels for the first time in three years Saturday, the government said, a week ahead of the Formula One night race.
The toxic smoke caused by burning to clear land for plantations is an annual problem for Indonesia's neighbours, but has been worsened this year by particularly dry weather.
"There has been a deterioration in the haze conditions in Singapore this afternoon," the National Environment Agency (NEA) said in a statement.
"This was due to a confluence of winds over the nearby region that led to more smoke haze from Sumatra being blown toward Singapore," it said, referring to one of the Indonesian islands where fires are raging.
NEA said the pollutant standards index (PSI) had reached 108 in parts of the island late afternoon Saturday.
An index reading between 101-200 is considered unhealthy, with residents advised against doing prolonged strenuous exercises outdoors.
Singapore may continue to experience hazy conditions over the next few days, the agency warned.
The city-state of 5.6 million people was shrouded in thin white haze, with a few residents seen wearing face masks, but there was no major disruption to daily activities.
The Formula One race is scheduled from Friday to Sunday on a street circuit in the Marina Bay financial district.
Formula One organisers did not immediately respond to queries about their preparations if the haze persists.
Neighbouring Malaysia has also been affected by the smoke, with air quality in parts of the country including the capital Kuala Lumpur reaching unhealthy levels over the past few days and triggering a diplomatic row.
In 2015, the index reached "hazardous" levels of more than 300 in Singapore, forcing the closure of schools. Indonesian forest fires were the worst in two decades that year, firing up smog that blanketed large parts of Southeast Asia for weeks.