Beijing: North Korea today (April 24, 2004) blamed human "carelessness" for the massive train explosion triggered by a short circuit on its border with China killing 154 people and injuring more than 1,300.

"The blast occurred due to a short circuit when an electrical pole nearby was knocked down after an oil tanker collided with two carriages loaded with amonium nitrate fertiliser during the shunting of wagons," Jang Song Gun, a North Korean official in charge of rescue efforts told Xinhua news agency in Ryongchon, the scene of the mishap.

"The fire caused by the short circuit ignited the oil tanker and the chemicals," he said.

North Korea's official media reported that the blast occurred "due to electrical contact caused by carelessness during the shunting of wagons loaded with ammonium nitrate fertiliser and tank wagons".

"The investigation conducted so far shows that the damage is very serious," it said.

At least 154 people, including 76 students, were killed and more than 1,300 were injured in the blast, Jang said.

The North Korean Government, which issued a rare appeal for foreign help, has expressed appreciation for offers of international humanitarian assistance in the devastating train explosion.