At around 1 p.m. a traffic police team near Tuong Chuc market in Thanh Tri District spotted a Mazda car with suspicious signs.
They flagged down the vehicle to check documents.
The driver seemed to slow down at first, but suddenly accelerated and drove straight at the officers.
One flung himself onto the hood and held on even as the driver drove rapidly away from the scene.
A video clip of a traffic police officer in Hanoi clinging on to the hood of a car that tried to mow him down. Video by VnExpress/Hong Hanh
After around 200 m it encountered a bus and slowed down, throwing the officer off the hood, before speeding away.
The officer was injured.
The Thanh Tri District police later identified the driver as Nguyen Viet Cuong, 20, of Thuong Tin District.
It was not his car; he had borrowed it from an acquaintance in Thanh Tri.
He was taken in at around 5:30 p.m. and later tested positive for drugs.