Freezing rain hit Beijing Thursday morning, leaving roads slippery and causing thousands of traffic accidents. 

Beijing Traffic Management Bureau said that by 11 am Thursday morning, more than 2,000 traffic accidents were reported. Two people were killed and two injured on the Beijing to Pingu district expressway, and there were 12 accidents involving 40 vehicles on the North Fourth Ring Road, the bureau said in a press release. 

Residents complained they were not warned of the weather conditions in time, although snow had been forecast for Thursday from the beginning of the week. Drivers, cyclists and pedestrians have complained that roads and sidewalks were not salted or gritted.

An anonymous employee from Beijing Environment Sanitation Engineering Group, which is responsible for gritting roads, said it has taken urgent measures against the freezing rain, although he refused to give specific details of the group's operations.

A manager from Beijing United Crescent Auto Rescue, surnamed Xu, told the Global Times that by Thursday evening, they had attended about 700 rescues. 

"In fact, we have received more than 1,000 calls; most of them were accidents caused by the slippery roads. This number is double compared to ordinary days," said Xu.

On the Jingcheng Expressway which runs from Beijing to Chengde, Hebei Province, there were at least 10 car accidents, according to witnesses.

A car salesman, Li Zhe, told the Global Times Thursday that he saw some 50 crashed cars on his way to Huairou district.

"The road is extraordinarily slippery today. During the journey I've seen lots of broken-down cars next to each other; obviously they crashed into each other," said Li.

Many people were also injured from falling on the slippery streets, according to Jishuitan Hospital in Xicheng district, which specializes in orthopedics, although they could not provide exact figures of casualties.

According to Beijing Meteorological Bureau, freezing rain fell in Chaoyang and Fengtai districts on Thursday morning. The bureau put up a yellow alert announcement on its website at 8 am Thursday, warning of icy roads.

However, Beijing residents complained they were not informed in time about the freezing rain.

A quick survey of 10 people by the Global Times showed none of the interviewees knew about the freezing rain beforehand.

A tea art specialist, who gave her surname as Zhang, told the Global Times she heard nothing about the weather.

"I regretted wearing high-heeled boots the moment I stepped outside. If I was warned that the road would be so slippery I won't do that," said Zhang.

Hong Dashi, a 35-year-old delivery man who drives an electric pedicab told the Global Times he had to ride extremely cautiously to avoid accidents.

"I've never experienced this weather  in Beijing before. The road looks normal, but it's actually covered with a thin layer of ice. I've seen many people fall. Since it caused so many problems,  why weren't we warned?" he asked.

Sun Jisong, chief meteorologist with the Beijing Meteorological Bureau told the Global Times Thursday afternoon freezing rain seldom occurs in Beijing.

"Freezing rain happens when the ground temperature is below zero. Raindrops from 1,500 meters supercool when they fall through a cold air layer which is 1,000 meters above the surface, and freeze on any object they land on," said Sun.

"The freezing rain had stopped by Thursday noon. In that situation roads would be slippery so I suggest that drivers be more careful," said Sun.

Sun said the roads would remain slippery until midnight.

China Meteorological Administration suggested on its official website that in freezing rain conditions, drivers should install tire chains on their wheels and avoid accelerating, passing, sudden braking and sharp turns. It also said salt should be spread on frozen roads to melt the ice.