North Korea is barely able to care for more than a thousand people wounded in a huge explosion, roughly half of whom are children, aid officials say.
Officials say many of the children have horrific injuries
A massive blast tore through the town of Ryongchon on Thursday, leaving more than 160 dead and 1,300 injured.
International relief efforts have been hit by North Korea's refusal to allow South Korean aid supplies to cross the heavily guarded land border.
South Korean aid is now likely to reach North Korea by sea.
Aid workers allowed to visit the blast site have spoken of the unprecedented access they were allowed.
They describe scenes of total devastation in a 200-metre radius around the explosion with catastrophically injured patients being treated in the hospitals nearby.
A school located close to the tracks appears to have borne much of the force of the explosion and children make up a disproportionate number of the injured at the Sinuiju Provincial Hospital.
Masood Hyder, a senior World Food Programme (WFP) official who visited the hospital, told the BBC, "Most the injuries are facial; many people have lost eyes. Some unfortunately have lost both eyes".
He said most of the injured, including many with burnt and gouged-out eyes, had been hit by hot air and burning grit from the explosion.
"If you were facing [the blast], you got it straight in the face," he said.
The disaster has given foreigners a rare inroad into the secretive state.
Workers at the local hospital were trying to cope with the disaster despite poor supplies but, said Mr Masood, "were freely admitting to us... they need everything".
Another WFP official, Tony Banbury, told the Associated Press news agency of how children were being treated atop filing cabinets at an overcrowded hospital.
"We saw children rolling and moaning in pain, many with a lot of cuts to the face and rudimentary twine stitching," he said.
North Korean officials say the blast happened when electric cables ignited explosive chemicals and oil that were being transported on a passing train.
China and South Korea have each promised $1m in aid to their neighbour.
But the South Korean aid effort suffered a blow with North Korea refusing to allow supplies into the country across the land border - one of the most densely-militarised zones in the world.
Red Cross officials said delivering aid by road would take about four hours. Sea transportation, the other alternative, would take two days.
North Korea is notoriously sensitive about the area around the demilitarised zone (DMZ) which separates the two Koreas, and negotiating any changes to procedures there is rarely swift.
North Korea has proposed discussing the South Korean offer at talks on Tuesday.
CORRECTION: A photograph that appeared in some versions of our story N Korea train blast 'kills many', published on Friday 23 April, was published in error. We said the photograph was an image of smoke from fires burning at the site of the North Korean accident at Ryongchon station. It was not, and we apologise for the mistake.