A drunken bus driver took students on a perilous ride after classes, swerving along on a major Fargo thoroughfare as the young passengers scurried up and down the aisle, authorities said Tuesday.

Responding to a motorist's report of reckless driving about 3:25 p.m. Monday, a police officer caught up to the bus, contracted by St. John Paul II Catholic Schools, outside Shanley High School.

The officer quickly detected signs of intoxication from Valley Bus driver Bruce A. Tweed, 71, of West Fargo, police said.

Tweed was put through field sobriety testing, and a preliminary breath test measured his blood alcohol content at 0.12 percent. The legal limit for bus drivers in North Dakota and others operating a commercial vehicle is 0.04 percent.

The motorist who alerted police said "the bus was swerving all over" on 52nd Avenue S., "with children running up and down the aisle," a statement from police read. No injuries were reported.

Upon the driver's arrest, Sullivan Middle School and Shanley students aboard were advised by school officials to contact their parents for a way home.

Mike Hagstrom, president for St. John Paul II Catholic Schools, said in a letter to families that "we are grateful that the children arrived … safely, that the citizen notified the authorities, and that law enforcement personnel did their work for public safety. … Valley Bus assured us that the shuttle bus would continue on Tuesday with a different driver."