"The children are Indian citizens. Norway has no right to keep the children in foster care," the toddlers' grandfather Monotosh Chakraborty told AFP outside the Norwegian embassy where he and other relatives began a four-day protest.
The case has stirred emotions in India and took on a diplomatic dimension last month when Indian Foreign Minister S.M. Krishna demanded that Norway "find an amicable and urgent solution."
India on Monday sent a special envoy to Oslo to meet the Norwegian foreign minister and other officials to discuss the case.
The two children, aged three and one, were removed from their parents in May last year by the Norway's Child Protection Services (CPS) which deemed they were not receiving proper care at home in the south-western town of Stavanger.
The parents, Norwegian residents Anurup and Sagarika Bhattacharya, have rejected the allegation and are fighting to return to India with their children.
The Indian government has told Norway that the children are being deprived of the benefits of being brought up in their own cultural and linguistic environment and should return to India as soon as possible
The grandparents said they were hoping for a final decision in early March.
"We want our children back and we need no lessons from Norway on how to raise children," Chakraborty said.
"We just have one plea: Norway send our children home," he added.
On February 17th, the Norwegian authorities allowed the parents to see their children for the first time in three months.
The welfare services have refused to detail why the children were removed, citing confidentiality, but have said such moves are made only in situations that endanger the child or where the child's needs are not sufficiently met.