BUENOS AIRES, Argentina (CNN) -- Smoke blanketed the Argentine capital Friday as brush fires apparently set deliberately consumed thousands of acres in the provinces of Buenos Aires and Entre Ríos.
A haze surrounds the Palermo neighborhood of the Argentine capital early Thursday.
The smoke, from about 300 fires, is blamed for at least two fatal traffic accidents this week that left eight people dead.
Sections of major highways and the Buenos Aires port, among the busiest in the world, have been closed. Incoming flights to the city's domestic airport, Jorge Newbery Airpark, have been diverted.
The Argentine government has blamed farmers looking to clear their land for crops and grazing for the fires, which are estimated to cover 173,000 acres (70,000 hectares).
"This is the largest fire of this kind that we've ever seen," Argentine Interior Minister Florencio Randazzo said Thursday.
Randazzo called the situation a "disaster."
As of Friday morning, little progress had been made extinguishing the blazes.
No rain is predicted for the next few days, but the National Meteorological Service predicts that the winds will change direction soon, dispersing the smoke.
On Friday morning, the National Roads Administration closed sections of the heavily traveled Panamericana Highway, which leads in and out of Buenos Aires. Spokesman Ernesto Arriaga said "visibility is 5 meters" (about 16 feet) in some sections of the highway.
"Covering highways with smoke just to clear a field of weeds is unforgivable," Cabinet Chief Alberto Fernandez told Radio Diez. "It's incredibly irresponsible."
Hospitals have reported an increase in visitors complaining of breathing problems, sore throats and burning eyes in the past three days.
Citing a high level of carbon monoxide in the air, officials have encouraged people not to exercise outside.
Schools in Pilar, a city in the province of Buenos Aires, were closed Friday because of the gray, thick air.
The smoke has obscured views of some of the capital's landmarks, such the Obelisco monument and the government house, Casa Rosada, and people were seen walking on the city streets covering their faces with clothes.
This month, Argentina's farmers suspended a three-week strike over a new government export tax on commodities.
The bitter lockout left grocery shelves empty and caused major friction between President Cristina Fernandez de Kirchner's government and Argentina's large agricultural sector. E-mail to a friend
Journalist Brian Byrnes contributed to this report.