Pak Rim Su, Head of the National Defence Commission’s Policy Department, said at a press conference on May 28 that the DPRK does not have a 130-tonne "Yeono (salmon)-class submarine, which the RoK says torpedoed its 1,200-tonne corvette, the Cheonan, in the Yellow Sea.

Pak stressed that it does not make any sense militarily that a 130-tonne submersible carrying a heavy 1.7-tonne torpedo travelled through the open sea into the RoK waters, sank the ship and returned home.

He also rebutted the RoK's allegation that salvaged fragments of the torpedo matched design specifications that appeared on brochures the DPRK allegedly sent to an unidentified potential buyer of its torpedoes.

The officer said the RoK-led multinational team was not in a position to conduct an impartial probe and attacked the RoK for rejecting the DPRK's demand to allow its own experts to investigate the cause of the sinking.

Also on May 28, Ri Son Gwon, a high-ranking military officer of the DPRK, dismissed as a "fabrication" a serial number hand-written on a torpedo fragment reading "1 bun" or number one.

"When we put serial numbers on weapons, we engrave them with machines," Ri said. "We use 'bun' only for football or basketball players," he said.

Meanwhile, the Korean Central News Agency (KCNA) on May 28 quoted a Foreign Ministry spokesman’s statement as saying the DPRK will employ ''ultra strong countermeasures” if the RoK refers the Cheonan incident to the UN Security Council for imposing further sanctions on the DPRK.

The spokesman also criticised the US for backing the RoK’s plan to punish the DPRK through the UN Security Council.