The U.S. Department of Transportation’s Federal Motor Carrier Safety Administration on Tuesday ordered the Fung Wah bus service “to immediately cease passenger service and provide its entire fleet of 28 motorcoaches for thorough and detailed safety inspections by qualified inspectors.”

Fung Wah is a low-cost bus carrier operating between New York and Boston. News of the suspension comes on the heels of the revelation that the Massachusetts Department of Public Utilities found cracks in the frames of many of the company’s buses.

Authorities warn that as investigators examine Fung Wah’s safety records and performance, additional actions against the company could be necessary.

Intercity buses are a popular option for cheap travel between cities in the Northeast. They’re  cheaper than a plane or train ticket and they spare travelers who don’t own cars or want to spend hours driving.

But safety is a concern for riders considering some of these low-cost carriers. A federal crackdown last year took dozens of intercity buses off of the road.

The surge in the number of these types of buses has created headaches for safety inspectors. The National Transportation Safety Board reported in 2011 that state and federal inspectors said there simply weren’t enough investigators to inspect and review all of these carriers.