About 50 people were attending the service at Mt. Zion United Methodist Church in Bel Air when a man entered brandishing a handgun, the Harford County Sheriff's Office said. No injuries were reported.
Wearing dark clothing and a ski mask, the thief ordered several children and their father to go up the aisles getting purses and wallets, then put them on a pile on the floor, said the Rev. Craig McLaughlin, who was in the front pew when the gunman barged in from the rear of the church.
He gathered them in a bag and, after ordering congregants to the front of the church, fled with an undetermined amount of cash and valuables, police said.
Several worshippers called police on their cell phones after he fled.