A UN Official in North Korea says some 300 among the 1,300 injured from Thursday's train explosion are in critical condition.

According to recent reports from aid workers in the North, the death toll from the train accident in Ryongchon has risen to 161. The reports also said some 2,000 houses were completely destroyed in the blast while more than 6,500 houses were partially damaged.

Meanwhile, international aid workers and diplomats in the North said Saturday that they had been allowed to inspect the site of the explosion but had returned to Pyongyang without being able to visit medical facilities where most of the injured are being treated.

As a result, Pierette Vulthi, a UNICEF representative in Pyongyang, said the North had consented to UNICEF's request for its aid workers to be able to visit Ryongchon again in a few days.

Beijing-based Red Cross spokesman John Sparrow also said that further investigation is imperative, citing the need for more information on the blast site and the surrounding area.