Federal regulators ordered Conyers-based Top Class Bus Co. to cease operations Friday, saying the bus line was “blatantly disregarding” safety regulations by failing to maintain buses and allowing drivers to work too many hours and falsify their driving logs.

The U.S. Department of Transportation said its “imminent hazard” order immediately blocks the company from providing bus service to passengers or allowing other companies or drivers to operate its buses without its approval.

Transportation officials said the action was announced Friday as part of a nationwide crackdown on unsafe motorcoach operators.

“Bus companies that operate outside the law, putting lives at risk, will be immediately taken off the road and closed for business,” Transportation Secretary Ray LaHood said Friday in a press release.

Top Class Bus Co., which operates daily trips between metro Atlanta and New York, could not be reached from comment Saturday.

During a four-day investigation of Top Class, federal regulators said they found that the passenger bus service allowed drivers to keep working in violation of federal limits on driver duty hours, and to falsify their driving logs to conceal those violations.

The agency also said the company ignored “critical” vehicle maintenance issues that drivers had noted in their daily inspection reports.

Federal rules limit the number of hours bus drivers can operate vehicles or be on duty between rest periods and per week. For instance, drivers can’t drive more than 10 hours or be on duty more than 15 hours without an eight-hour rest period.