Officers responded to a report of children without an adult at a park Sunday afternoon, according to The Associated Press, and took the 10-year-old boy and 6-year-old girl to Maryland Child Protective Services.
The children have since been released to their parents, Danielle and Alexander Meitiv, Montgomery County police told ABC News today.
No charges were filed but the incident is being investigated, the AP reported.
Danielle Meitiv posted on Facebook this morning that the “police coerced our children into the back of a patrol car, telling them they would drive them home. They kept the kids trapped there for three hours, without notifying us, before dropping them at the Crisis Center, and holding them there without dinner for another two and a half hours."
“We finally got home at 11 pm and the kids slept in our room because we were all exhausted and terrified," she wrote.
Maryland law says that children younger than 8 must be under the care of a person who is at least 13, according to Child Protective Services.
Earlier this year, the Meitivs were "found responsible for unsubstantiated child neglect" by state Child Protective Services after they were investigated for allowing the children to walk home alone from a neighborhood park about one mile from their home, authorities said.
"We are shocked and outraged that we have been deemed negligent for granting our children the simple freedom to play outdoors. We fully intend to appeal," Danielle Meitiv told "Nightline" via email at the time. "We also have no intention of changing our parenting approach."
It all began in December when police stopped the kids as they were walking home from a park without an adult, and gave them a stern warning. Child Protective Services then accused the Meitivs of neglect, saying unless they committed to a safety plan, the kids would have to go into foster homes.
In a previously aired "Nightline" interview, Danielle Meitiv said, "Frankly I think that raising independent children and responsible children and giving them the freedom that I enjoyed is a risk worth taking."
"In the end, it's our decision as parents," she added.
The Associated Press contributed to this report.