Wearing a protective mask a man looks on while walking on Moscow's Red Square. MOSCOW (AP) — The number of wildfires in Russia has shrunk significantly, but clouds of acrid smog generated by them still hung over the Russian capital Wednesday, officials said.

A cold front advancing from the west later this week is forecast to finally put an end to the unprecedented two-month spell of heat.

The level of carbon monoxide, hydrocarbons and other pollutants in the air continued to exceed safe limits Wednesday, said Mosecomonitoring environment watchdog.

Smoke has periodically shrouded large sections of the city since the weekend, but pollution remained below its peak levels from earlier this month when smog choked the Russian capital for a week.

The area covered by wildfires around Moscow has been halved since Tuesday, but four forest and five peatbog fires are still burning, the Emergency Situations Ministry said.

The amount of land on fire countrywide dropped by about 10 percent, to some 20,000 hectares (nearly 50,000 acres), in the last 24 hours. This is an area 10 times smaller compared to the territory the blaze covered at its peak earlier this month, the ministry said.

Roman Wilfand, the head of the main Russian weather service, said that a cold front would bring storms and heavy rains that would sharply cool temperatures in western Russia starting Thursday, offering the exasperated Russians a much-desired break from scorching heat.

The hottest summer since records began 130 years ago has sparked thousands of fires in Russia. More than 50 people have died directly in the wildfires across Russia, and more than 2,000 homes have been destroyed.

The number of deaths recorded in Moscow had doubled to an average of 700 per day during the worst of the scorching heat and smog, city officials said.

Drought has cost Russia a third of its wheat crop, prompting the government to ban wheat exports through the year's end.