A joint United Nations-Red Cross team on Sunday met in Pyongyang to discuss further aid to the devastated area of Ryongchon near the Chinese border.

North Korean officials have told diplomats and aid workers that more than 150 people were killed - more than half of them schoolchildren - some 1,300 people were injured and nearly 2,000 homes were destroyed or badly damaged in Thursday's blast. Unofficial arrestment put the casualty figures much higher.

The Red Cross, on Sunday, said they urgently need more information in order to help, especially whether hospitals have enough medical supplies to treat the injured.

Just across the Yalu River, in Dandong, China, one hospital was prepared for an influx of injured but apparently none have been permitted to leave North Korea for treatment.

North Korean state-controlled media rarely make mention of any domestic disaster. But in a dispatch 48 hours after the incident, the Korean Central News Agency acknowledged the explosion, saying the government is trying to save the lives of the injured.

The government's short-wave broadcaster Voice of Korea, quoting the KCNA dispatch, also mentioned the international relief effort.

"We appreciate the governments of different countries and international organizations… for expressing their willingness to give humanitarian assistance," he said.

North Korea says the blast happened when rail wagons carrying ammonium nitrate fertilizer and fuel oil collided. Other reports say explosives being carried by rail to a tunnel construction site triggered the explosion.

The explosion destroyed virtually everything within 500 meters of the railway station, which was an economically important link to China, its closest ally and a source of aid.

Russia has offered a planeload of humanitarian aid. China and South Korea are each offering more than million worth of emergency aid. The United States, European Union and Australia have also offered help.

The South Korean Unification Ministry on Sunday says Seoul will ask Pyongyang for a meeting to discuss how aid could be transported across the border. The ministry says South Korea will also make an offer to send a 25-person medical team and a hospital ship to the North.

Humanitarian workers allowed by the North Korean government to travel to the blast site have described a scene of utter devastation. They say roofs of buildings several kilometers away from the railway station were blown off.

The U.N. office for the Coordination of Humanitarian Affairs says 40 percent of Ryongchon was destroyed. Concern is also being expressed about shelter for the thousands of people made homeless.