Child Protection Services have again seized the two 'free range' children of a mother and father whose unusual approach to parenting has become a national debate. Danielle and Alexander Meitiv, both scientists in Maryland, made headlines just before Christmas when police found Rafi, 10 and Dvora, six, wandering the sidewalk on their own. On Sunday, a concerned citizen reportedly called authorities once again after seeing the siblings unaccompanied near a neighborhood park around a third of a mile from their home. The children were picked up by police, who say they followed protocol by turning them over to CPS. Meanwhile, Mrs Meitiv tells Fox 5 DC that CPS workers left her and her husband to panic for hours before letting them know their kids were safe. Picked up AGAIN: The Meitivs say they were left to panic for hours by CPS workers after their children--who they raise with a so-called 'free-range' approach--were picked up by police for the second time in two months while walking down the street alone . Taught a lesson? The Meitivs say their kids Dvora and Rafi went missing starting around 6pm. They were not reunited with them until 10:30 . What's more, the elder child, Rafi, insists the scariest part of the hours-long ordeal was being picked up by police. ‘They kept the kids for hours,’ a shaken Danielle Meitiv told Fox 5 after being reunited with them. ‘It’s 10:30 at night. They’ve been missing since 6 o’clock…Somebody called 911 and the police called CPS and they decided to bring the kids here and they didn’t call us.’ According to Mrs. Meitiv, the children were expected home no later than 6:30. When 6:30 came and went, they became frantic. They would not receive a call from CPS until 8pm. Even then, they say they weren't reunited with their children or even told where they were for hours. in the interim, Rafi tells Fox 5 that initially he believed the responding police officer was simply offering them a lift. Rafi said: . ‘The policeman said “We’ll give you a ride home” when we were like two blocks away. And two and a half hours later, after sitting in the car two and a half hours, he said “I’ll bring you home” and, instead, he brought us here.’ 'Besides the policeman pulling up...no': Asked if he was scared during the hours-long ordeal Sunday, 10-year-old Rafi admitted he was, but not because he'd been left alone with his sister . Seized: Officials seized six-year-old Dvora (left, far left) and 10-year-old Rafi (left, blue hat) on Sunday in a Maryland park. Their parents Danielle and Alexander Meitiv are pictured, right, going to confront CPS officials . Free-range parenting is the name given to a style of raising kids in opposition to so-called 'helicopter parenting'. 'Helicopter parents' are named for their habit of hovering over their offspring, micro-managing their lives in an attempt to keep them safe. However critics believe this creates under-confident, over-reliant children, while also causing the parents stress. Free-range parents advocate a more hands-off approach, where children are allowed to go out and experience the world on their own. Instead of constantly monitoring activities to make sure children are safe, the emphasis is put on adults assessing risk ahead of time, and equipping children with the skills to deal with danger themselves. 'Here' was Child Protective Services, Rafi said. And as he and his sister sat waiting to go home, their parents say 'upper management' at CPS was involved in keeping that from happening. Only at 10:30pm did Mrs. Meitiv say she was reunited with her children and only after promising not to let them off the leash. ‘They made us sign a safety plan that says we will not leave them attended at all until they follow up, . 'And I’m not gonna risk my kids being snatched again like this by CPS.' When questioned, the Meitivs say they believe in a so-called 'free-range' approach to parenting, which encourages independence from infancy. In March, the CPS found the couple guilty of neglect for letting the children walk home from school alone. It meant the agency would start a file on the family's activities and whereabouts for at least five years. The Meitivs hit back at the ruling, insisting they would continue to bring up their own children as they see fit - whatever the consequences. Unsubstantiated child neglect is not a criminal charge, but is in most cases a prelude to such charges. It usually comes when the CPS has deemed parents to have neglected their children, but has insufficient information or witnesses to press charges or take action. Parenting style: The Meitivs believe in giving children an unusual amount of independence from a young age . This seemingly arbitrary ability to place a family under investigation and rule against them has left the Meitivs, who both work as scientists, furious. In March, Danielle Meitiv told the Washington Post they were planning to appeal the decision. 'We don’t feel it was appropriate for an investigation to start, much less conclude that we are responsible for some form of child neglect,' she told the Post. 'What will happen next time?' she said. 'We don’t know if we will get caught in this Kafkaesque loop again.' On December 20, police in Silver Spring picked up Rafi and Dvora walking home on a Saturday afternoon from the park after a member of the public reported it. The Meitivs told police they often let their children walk on their own and that the kids knew the area well. The CPS sent the Meitivs a letter on February 20 informing them their investigation had been closed and told the Washington Post they would not be commenting on the process. Outraged, Danielle Meitiv said she does not see why it is wrong to give her children independence. 'We're just doing what our parents did. It was considered perfectly normal just one generation ago,' she said on Today in January. Guarantees: As part of their free-range parenting philosophy, the Meitivs make sure their children carry these badges in case someone worries and asks while they are out on the street . Defiant: Danielle and Alexander have said that they will continue to bring up their children as they see fit . Meitiv admits that the walk back from the park was longer than her two kids had taken before, but says she wasn't worried because they have been on several shorter walks together with no issues. 'Well I've walked home from school before. Not with my sister, but I've done it alone,' 10-year-old Rafi said. 'We walked around the block a lot and we walk home from another park which is just around the block. The Meitivs describe themselves as 'free-range parents' who encourage their two children to take journeys without supervision in order to build confidence and teach them about the outside world. Both parents are highly educated. Alexander Meitiv is a Research Fellow at National Institutes of Health and Danielle is an Oceanographer. Usually they have the kids carry around a card that reads 'I'm not lost. I'm a free range kid' but they left them behind that day when they went to the park that was a bit further away from their house. Asked what the CPS would do the next time they are called, they said they would simply follow procedure. What's wrong? Danielle Meitiv (right) appeared on the Today show in January with her 10-year-old son Rafi (center) and 6-year-old daughter Dvora about a month after Child Protective Services launched an investigation because she let the two walk home from a park alone . Parenting choice: Mrs Meitiv (pictured) says she and husband Alexander often let their children Rafi, 10, and Dvora, 6, walk alone to teach them about the world . 'If we get a call from law enforcement or from a citizen, we are required to investigate. Our goal is the safety of children, always,' said Paula Tolson, spokeswoman for the Maryland Department of Human Resources to the Washington Post. The free range parenting trend was first popularized in 2008 by New York journalist Lenore Skenazy, in a piece entitled Why I Let My 9-Year-Old Ride the Subway Alone. She was railing against helicopter parenting and speaking to the Washington Post said that she was appalled by the ruling against the Meitivs. 'The go-to narrative in the last 20 or 30 years for parents was, "Take your eyes off your kid for even a second and he’ll be snatched." What the Meitiv case did was pivot the story to: "Give your kid one second of freedom and the government will arrest you."’ Speaking about her horror at the decision, Danielle Meitiv said she turned to her husband and felt humiliated. 'I was kind of horrified,' she said. 'You try as a parent to do what’s right. Parents try so hard. Even though I know they are wrong, it’s a painful judgment.' Journey: On December 20, the brother and sister were walking about a mile home from this park when a citizen called 911 after seeing the two without their parents .
Police seized Rafi, 10, and Dvora, 6, in a Maryland park on Sunday and their parents say they weren't reunited by CPS for hours .
Scientists Danielle and Alexander Meitiv believe in 'free range parenting' meaning the children are afforded total independence from infancy .
The Meitivs were found guilty of neglect in March. After Sunday's incident they were forced sign a paper pledging not to leave them unattended .