Fifty electric motorcycles from the police force have been pulled from daily operation after another two were damaged in a blaze that broke out at Ngau Tau Kok police station early Friday.

It was the first time the US-made Zero S ZF9 motorcycle burst into flames since the fleet went into full operation in Hong Kong two years ago.

The two motorbikes were being charged at the police station’s car park on Siu Yip Street when one of them burst into flames at about 1.15am Friday.

Police said the fire spread to the other motorcycle and a police van, damaging all three vehicles.

Firemen fought the blaze with a hose and doused the flames shortly after 1.30am. No one was injured, and firefighters found no suspicious cause.

“Initial investigation showed a short circuit was the suspected cause,” a source said to South China Morning Post.

He said the police, the Electrical and Mechanical Services Department and the Hong Kong agent of the manufacturer were investigating. The source said the force’s 50 other electric motorcycles were pulled from operation as a safety precaution until the cause was established.

Police said the 52 Zero electric motorcycles were delivered to frontline traffic policemen for daily patrols in five police regions in 2014 after a pilot scheme in 2013.

The force said the model has a top speed of 121km per hour and can cover 183km on a single charging. Its battery takes four and a half hours to fully charge.

Have you ever considered getting an electric bike? Do you think they’re safe?