Poland's Ambassador to Pyongyang says North Korea has told foreign diplomats it had discharged two detonations last week to demolish a mountain for a hydroelectric project in the north of the country.

In an interview with Japan's Kyodo News Agency Friday, Ambassador Wojciech Kaluza said he had received the report from an official of his embassy who was among the eight foreign diplomats who were allowed on Thursday to visit the site of last week's blast.

Kaluza quoted his embassy official as saying that the group of diplomats had seen one of the two explosion sites.

Kaluza added that local construction authorities had explained to the diplomats the kind of explosives used for the demolition work and the size of the land that was destroyed in the process.

However, the Polish ambassador was quick to add that the group of diplomats has yet to confirm the veracity of Pyongyang's claims that the blast was part of demolition work for a hydroelectric dam.