The girls have been unofficially identified as sisters Sofie, 9, and Marlene Marie, 10, from the small Danish town of Hadsund, where the school held a memorial on Sunday, the Berlin paper Tagesspiegel reported on Monday.
Their bodies were found in the burned-out car in the woods near Börnicke, while their father, named as Peter R., was taken to Berlin's Marzahn specialist burns hospital for treatment after staggering out into the A24 road in the early hours of Saturday and stopping a car.
He was put in an artificial coma on Saturday and can therefore not be questioned by police, who suspect that he may have set the car on fire while the girls were asleep on the back seat.
A police spokesman from the Danish North Jutland force told Danish news agencies that the identities of the children were almost 100 percent certain.
Danish newspapers reported over the weekend that their father was separated from his former wife and the girls, but that he had posted on Facebook that his daughters had visited them at Christmas and for his 40th birthday at the end of March.
It remains unclear why he had travelled to Germany with them, or whether he had done so with the permission of their mother.