Construction workers Wednesday discovered two 100- kilo WWII bombs concealed in a road bridge pillar in the south- eastern Czech town of Znojmo, police said, dpa reported.
"Colleagues from the bomb squad said they have never seen anything like this. They only read about it in the literature," police spokeswoman Lenka Drahokoupilova told Deutsche Presse-Agentur dpa.
An excavator operator working on the bridge unearthed a 30- centimetre-wide and one-metre-long bomb inside one of the stone- lined, dirt-filled pillars.
The bomb squad then stumbled upon another one next to the first find, detonating both at the site.
The bombs were Russian-made but likely placed by retreating Nazi forces at the end of World War II, Drahokoupilova said citing the explosives team at the scene.
Cars had been driving above the bombs for over six decades but they posed no danger as they were not fitted with a fuse, she said.
The bomb squad is due to return Thursday to continue checking the bridge.