A portion of the military site, located in the commune of Niederanven Google Earth screenshot

A portion of the military site, located in the commune of Niederanven Google Earth screenshot

Four people were inside a depot “and were handling an artillery shell,” the public prosecutor’s office said in a press statement on 14 February.

Two were killed by the explosion. Two others have been hospitalised, one in “critical” condition.

The explosion took place at around 10:30am, according to the prosecutor’s service. A witness told RTL that the explosion was heard more than 100m away.

Maurice Fick, a journalist at the Wort, said on his Twitter account that a new ambulance arrived at the site around 12:40pm and left 15 minutes later.

Two investigating magistrates have began an inquiry, the prosecutor’s office said. The defense ministry said it would hold a press conference later on Thursday afternoon.

Luxembourg's prime minister Xavier Bettel issued a statement on Thursday afternoon expressing his condolences.

"I was deeply shocked to hear the news of this tragic event. Two Luxembourg noncommissioned officers died while carrying out their duties in the service of the country. Two of their comrades were wounded, one seriously. My thoughts are with the victims, their families and their loved ones. The government shares their suffering and stands with them at this difficult moment. This event reminds us in a brutal way of the dangers to which our soldiers are exposed on a daily basis as part of their missions in the defence of our country. Their commitment deserves the deepest respect of our entire society. "

Updated 14 February at 5pm with quote from prime minster Xavier Bettel