Child traffickers are targeting the youngest and most vulnerable survivors of Burma's catastrophic cyclone and two suspects have already been arrested, the UN said.

The children, among up to two million people struggling to survive without enough clean water, food or shelter in the aftermath of the storm, were approached last week in the main city Rangoon, it said.

"A broker came to a shelter and tried to recruit children," said UNICEF's chief child protection officer in Burma, Anne-Claire Dufay.