(NASHVILLE) A gunman killed at least three children when he opened fire Monday at an elementary school in Nashville, Tennessee, police said.

The shooter was shot dead by law enforcement, police also said on Twitter.

Nashville Fire Department wrote on Twitter that there were “several patients,” but their condition was not immediately released. The shooting happened at The Covenant School, from where the students walked holding hands to a nearby church to find their parents.

Firefighters said they responded to an “active aggressor,” but did not elaborate. Further details about the shooting were not immediately available.

The Covenant School has served about 200 students from kindergarten through sixth grade in recent years and was founded as a ministry of the Covenant Presbyterian Church in 2001, according to the school’s website.