Rail traffic is expected to continue through a small North Dakota town at the center of latest oil train debate before the weekend, rail company BSNF said.

Six of the 107 cars carrying Bakken crude oil through Heimdal, N.D. caught fire after derailing Wednesday. BNSF said most of the oil still in the derailed cars was removed and rail traffic should continue through the area before the weekend.

"BNSF crews are currently working to clean up the area, remove the derailed cars, and repair the damaged track at that location," the company said in a late Thursday statement.

Fires associated with the derailment were extinguished Thursday afternoon. The 40 or so residents of Heimdal who were evacuated after the incident were cleared to return home.

The Department of Transportation last year called for the elimination of older rail cars designated DOT-111 for shipment of flammable liquid, "including most Bakken crude oil," the type found in North Dakota. The cars involved in the Heimdal derailment were newer CPC-1232 models, which federal regulators said were only marginally better than DOT-111 cars.

Last month, BNSF said it would require trains hauling crude oil to reduce their speeds in communities with more than 100,000 residents and work to remove all rail cars designated DOT-111 from service within a year and phase in CPC-1232 models.

North Dakota is the No. 2 oil producer in the nation and the pace of increase in output from shale has exceeded pipeline capacity, leaving energy companies to rely on rail to take up the slack.

Federal authorities have focused on railcar design as a safety measure, a contentious matter for the energy industry. North Dakota Gov. Jack Dalrymple said the latest incident was further evidence of the need for expanded pipeline capacity through his state.