At least 154 people, including 76 students, have been confirmed killed in Thursday's train explosion at the Ryongchon railway station in North Korea, China's official media reported on Saturday from the site of the accident, which is close to the Chinese border.
The number of people injured was not given. However, earlier reports suggested that the figure might be around 1,500.
Xinhua news agency said the toll was provided by Jang Song Gun, a senior North Korean official in charge of rescue efforts at the scene of the accident.
Xinhua is one of the few foreign media allowed to work out of North Korea.
The report came after North Korea released a statement saying "carelessness" caused the explosion.
It was the first official reaction from the Stalinist state on what caused the blast.
The country's state news agency reported that electrical contact detonated train cars loaded with a chemical component of fertiliser.
The Korean Central News Agency statement expressed gratitude for offers of help from countries and aid agencies.
A UN interagency mission will "mobilise immediate support and assistance to the people in the afflicted area", UN Secretary-General Kofi Annan said.
The Office for the Coordination of Humanitarian Affairs and the World Health Organisation will lead the mission.