MINNEAPOLIS (AP) - Railroad documents released by the state Department of Public Safety show about 50 trains carrying crude oil from North Dakota are passing through Minnesota each week.

The documents obtained by The Associated Press were first reported Saturday by the Star Tribune.

They show that nearly all of the oil trains pass through populated areas. Ramsey County averages about 45 trains a week, as does Clay County, which borders Fargo, North Dakota.

Reports say each train carries more than 1 million gallons of crude oil.

The railroads were required to provide the traffic flow summaries to states so first responders could prepare for potential emergencies. Federal regulators have been under pressure to improve oil train safety after several derailments, including one that killed 47 people in Quebec last July.