Four people were injured Thursday in two explosions at a munitions disposal facility in eastern Germany, according to dpa. The first explosion at Nammo Buck GmbH in Pinnow, near the Polish border, injured two 33-year-old employees, the company said. One was seriously injured and taken to hospital in Berlin by helicopter, the company and police said. A second explosion injured two firefighters, they said. The blasts occurred as workers were carrying out a series of tests while destroying munitions, Nammo said. No buildings were destroyed, it said. The company did not say which weapons were being handled at the time of the blast. What caused the explosions was not immediately known, but Nammo promised it would quickly be determined. Nammo Buck, located about 100 kilometres north-east of Berlin, was the site of a 2004 accident that killed one worker while he was preparing to destroy munitions in a controlled explosion in a vacuum chamber. The facility is owned by the Norwegian firm Nammo, which said on its website that the Pinnow operations dismantle missiles, rockets, ammunition, mines, hand grenades and detonators used by the former East German and Soviet armies. The arms are disposed of or recycled. Weapons from Western countries are also destroyed there, including the majority of the German army's cluster bombs, which are illegal under an international treaty that went into force in 2010.