Fog shrouds eastern Chinese provinces Monday and disrupted traffic, while Beijing saw a rare sleet in November.

Two people were missing after two freighters collided in the waters off Zhoushan, Zhejiang Province, in a thick fog at 4:30 a.m., said a spokesman with the Zhoushan Bureau of Maritime Affairs.

The two were from a sand freighter that sank after the collision, the spokesman said.

In Shandong Province, visibility dropped to well below 50 meters due to heavy fog in Qingdao, Yantai, Weihai, Dezhou and Weifang cities, forcing the closure of a dozen of highways.

Meanwhile, ice droplets about 2 to 5 mm in diameter were reported falling across Beijing.

The capital's meteorological station said the icy rain would be followed by snow Monday evening, and the sleet would continue to Thursday.

Zhang Mingying, senior engineer with the station, said sleet in Beijing was rare in November, and the average temperature this week was about six degrees Celsius below average for the time of year.

December was the usual month for icy weather, he said.

Beijing residents are not familiar with frozen rain. A man surnamed Wei said he thought it was hail.

"The ice battered my car window as I was driving along Chang'an Avenue. I was surprised," he said.

"It hit the windows of my home loudly, and I was surprised it was not rain but ice," said a resident of Wanjing community in eastern Beijing.

Zhang Qiang, director of the Beijing Weather Modification Office, said the office had not used artificial means to accelerate the rain on Monday, but it would monitor the clouds and, if necessary, resort to means to enhance the rain or snow to ease the lingering drought.

The office launched weather rockets to enhance Beijing's first snow fall this year on Nov. 1.

"We won't miss any opportunity for artificial precipitation since Beijing is suffering from a lingering drought," said Zhang.

The Beijing Environment and Sanitation Engineering Group Co. Ltd. had made preparations for the pending snowfall.

Zhang Zhiqiang, an official in charge of road cleaning in the company, said it had prepared 2,000 tons of snow-thawing agents and had 420 workers on post and 126 snow-clearing vehicles ready for melting and clearing ice and snow from the roads.

Neighboring Henan and Hebei provinces also saw rain and sleet on Monday.

The Hebei provincial meteorological station said the temperature this week would drop 8 to 10 degrees to below freezing from the average of 5 degrees Celsius last week.

Zhou Jikun, deputy director of the Hebei Provincial Center of Disease Control, said respiratory diseases were more likely to occur during drastic temperature drops. The lingering haze over the last week had already caused a rise in the number of patients of respiratory diseases in the province.

He said 80 percent of more than 200 flu virus samples taken from hospitals in the provincial capital of Shijiazhuang during last week tested positive for A/H1N1, according to the centers monitoring.

The province has reported one death from the A/H1N1 flu virus by the end of October, but most patients have been cured, according to the center.

In Changchun, capital of northeast China's Jilin Province, roads became slippery on Monday, after an overnight snow was frozen on ground.

Several minor road accidents caused temporary traffic congestions, but no casualties were reported, said a spokesman with the city's communications department.

A Changchun man surnamed Wang said a 10-minute ride to work took him one hour on Monday. "Cars moved very slowly. You can hear the cracking of the ice on road."