International aid organisation Save the Children has been able to reunite 69 children with their families in Nepal in the aftermath of flash flooding on Wednesday.

Two young brothers are among the 35 Australian tourists caught up in the tragedy in Nepal, after a deluge of ice and rock destroyed parts of its border with China.

An immigration checkpoint has reportedly been swept away in Nepal's flash flooding, as family of missing New Zealanders appeal for any information on people in the area.