Unregistered motorcycles and powered tricycles will be seized and riders and drivers who do not have licenses will be detained as part of efforts to control the increasing number of the vehicles in Beijing.

A campaign against the illegal use of the vehicles started on Monday amid fears about the safety of drivers and passengers.

"These motor vehicles pose a threat to passenger safety," said Li Shaoming, deputy director of the Beijing Traffic Management Bureau.

In the first seven months of 2014, 78 passengers died in accidents involving motorcycles and powered tricycles in the capital, 41 more than in the same period last year.

Unregistered vehicles tend to be found at tourist sites, markets and junctions and often cause traffic chaos, Li said.

"The bureau has received more than 6,000 complaints and calls for strict management," he added.

Motorcycles and tricycles powered by electricity or fuel are classed as automotive vehicles, the same as cars, under municipal rules. They should therefore have registration plates, and the driver should have a license.

Plates are not issued in Dongcheng, Xicheng, Chaoyang, Haidian, Fengtai and Shijingshan districts.

"Most of these vehicles in the city are used illegally," Li said.

Tricycles used by delivery companies are not included in the campaign. Regulations will be introduced to ensure they are operated safely.

"We support controls by the authorities," said a tricycle owner who declined to be named.

The man, who is in his 40s, has picked up passengers near subway stations for a year. He said he is aware of the safety risks.

"The root of it lies in the drivers' failure to obey traffic regulations," he said, adding that he will give up the business if the government imposes the measures strictly."

"But it's difficult to ban all the vehicles because there is always a demand for them."

The interview was interrupted by a young woman in a hurry who hired his tricycle.

Other tricycle drivers nearby said the man had waited outside Huixinxijienankou subway station for less than 15 minutes before picking up the woman.

Shan Yongjian, 29, who uses illegal tricycle taxis, said there should be some leeway to allow the vehicles to serve passengers like him.

"When I come to a strange place, or the weather is bad, legal taxis are often not available or are too expensive," he said. "At such times tricycles are greatly needed."

Gao Fei, a 24-year-old who works in the Zhongguancun area, was injured by a tricycle that hit his leg as he was walking.

"I support the crackdown," he said. "Tricycles should be banned to protect people's safety."

zhengjinran@chinadaily.com.cn