NEW PRAGUE — A Minnesota school district locked down several buildings Wednesday after a 911 call that authorities later said was a prank, and a 12-year-old boy suspected of making the call was arrested.

The 8 a.m. emergency call prompted a lockdown at the middle school, high school and Central Education Campus buildings in New Prague, 45 miles southwest of Minneapolis. The male caller said he was inside one of the school buildings, Scott County Sheriff Kevin Studnicka said.

“He claimed he needed help because there was a shooter in the building with an AK-47 and that there were a couple of victims,” Studnicka said. When dispatchers asked for the caller’s cellphone number, he claimed it was a new phone and he didn’t know the number, the sheriff said.

Police Chief Mark Vosejpka said police and deputies quickly determined no one was hurt and zeroed in on the 12-year-old boy. Vosejpka didn’t explain what led them to suspect the boy.

Parents rushing to the scene were directed to a nearby church. Students were dismissed from the schools by late morning. Classes were canceled for the rest of the day but were expected to resume Thursday.

The middle and high schools have a combined enrollment of 2,067.

It was the second such disruption in the district this year. Two months ago, a student phoned in a bomb threat, Superintendent Larry Kauzlarich said. That student was expelled.