BRUSSELS, Feb. 14 (Xinhua) -- Two soldiers died on Thursday morning after a 48-kg World War II shell exploded in a munitions depot of the Luxembourg army, Belgian media reported.

The two victims, aged 40 and 48, were non-commissioned officers (NCOs), according to a report submitted Thursday afternoon by the Minister of Defense Francois Bausch.

Two other people, aged 41 and 44, were hospitalized, one of them in critical condition.

The men were preparing to ship the package containing the WWII shell for transport to Belgium before it exploded and left two of the victims dead.

The accident occurred during an operation "that we have already done multiple times", said Alain Duschene, the Army Chief of Staff who could not recall what type of weapon it was.

"If they are small, they are neutralized at the Waldhof. Otherwise they are sent abroad," added the Assistant Crown Attoney George Oswald.

The soldier that lies in critical condition was allegedly operated on Thursday afternoon, while the one carrying minor injuries is expected to be interviewed for the purpose of the investigation.

He will be asked details regarding the exact circumstances of the accident. An investigating judge has ordered an autopsy of the victims and the material will subsequently be analyzed abroad.