Beijing, March 19 : Beijing was hit by heavy snow, with blizzards in part of the Chinese capital, the local meteorological authorities said. The snowfall is expected to linger and visibility in most of the city could drop below 1,000 metres, said the Beijing Meteorological Service. As of 6 p.m. Friday, the city had issued a blue alert for heavy snow, and yellow alerts for road icing and thick fog, reports Xinhua news agency. By 5 p.m., Beijing had sent about 42,000 sanitation workers and 3,461 vehicles for snow clearing work, local authorities said. According to the latest weather forecast, the city's minimum temperature is expected to drop to about minus 2 degrees Friday night, and its mountainous areas will see the lowest temperature of minus 8 degrees. China has a four-tier, colour-coded weather warning system, with red representing the most severe alert, followed by orange, yellow and blue. /IANS