YUROP

From the article:

According to the reports, soldiers failed to unload part of the train carrying over 1,000 tons of explosives in total, and the anti-tank mines continued to circulate around the country before they went missing.

Maybe Ikea needed the space to transport something, so they unloaded everything forgotten on the train.

Militaries surprisingly frequently loose weapons around the world:

• https://taskandpurpose.com/news/lost-stolen-military-weapons/
• https://nationalinterest.org/blog/reboot/us-military-missing-six-nuclear-weapons-180032

Or they just wanted to support SCP-3008, but accidentally sent to a normal ikea ;)

Pänzerbüm

Ich verstehe nicht.