Traveling on two wheels is often the best way to maneuver through Thailand's notorious traffic. However, the Department of Land Transport has put the brakes on motorbike-hailing services offered by Uber and Grab barely two months after they started.

Department of Land Transport official Nanthapong Cherdchoo said both UberMoto and Singapore-based GrabBike were operating illegally and their privately owned motorcycles lacked proper registration as public transport vehicles. The department warned the two companies on Tuesday that they could face harsh legal action if they continue their services.

Uber said it will fight to continue its experiment with a motorcycle-hailing service.

"This is a temporary pause for a global pilot," Uber spokeswoman Amy Kunrojpanya said in a statement. "We hope to resume services as quickly as possible and have every reason to believe, based on the positive and productive discussion we are having with the relevant authorities in Thailand, that this is possible."

Uber says it has been holding talks with transport officials on creating regulations to legalize ride-hailing in the country, as current laws do not provide for app-based transportation services. However, the company's car-hailing services remain in operation.

Motorcycle taxis are ubiquitous in Bangkok, with drivers licensed by the government. Commuters hop on behind the driver and usually travel short distances. But many commuters are reluctant to use them because of safety issues. Uber and Grab added a new dimension to that service by equipping drivers with their mobile phone app and promising safe rides. Many motorcycle taxi drivers have been upset by the new competition.

A motorcycle taxi driver was widely shown on social media driving off after pulling a GrabBike driver's keys from the ignition. The driver was upset that a student had summoned a GrabBike instead of using the area's motorcycle taxi services. But on May 11, police apprehended the GrabBike driver, who was fined 4,000 baht ($115) for using a private vehicle for public transport. The motorcycle taxi driver was let off with a warning.

GrabBike appeared to be continuing its operations Thursday despite the Department of Land Transport order, with clients still able to request rides on the Grab smartphone app.