Five street sweepers were killed and two more were injured when they were struck by a car on Erhuan Bridge in Harbin, Heilongjiang province.
The driver, surnamed Li, has been detained by local police for suspected drunken driving.
Although Li claimed that failure of his steering wheel was to blame, police said, tests found that his blood alcohol level was 146 milligrams per 100 milliliters.
In China, it is a criminal offense to drive with a blood alcohol level above 80 milligrams per 100 milliliters.
The incident occurred at Erhuan Bridge above the intersection of Kang'an and Qianjin roads in Harbin's Daoli district at 4:40 am. The seven workers hit by Li's car were cleaning the ground at the time. Four of the victims died at the scene and a fifth died at the hospital.
Liu Xifan, one of the two injured workers said there were 11 people doing cleanup work at the time.
"The car ran so fast, like an arrow off a bowstring," Liu said. "The car knocked me down and then knocked several colleagues away."
The two injured workers were treated at Harbin Red Cross Central Hospital. Tang Xiaoguang, director of orthopedics at the hospital, said their injuries are not life-threatening.
They have received surgery after they were diagnosed with bone fractures - one person in the right arm and the other in the right femur, Tang said.
The driver may have been offering taxi services, as witnesses said his car was printed with the name of an online ride-hailing app.