"The current status of mine suspected areas in the Republic of Croatia amounts to 195.2905 square miles," the center noted. That cover 10 counties -- "77 towns and municipalities contaminated with mines and unexploded ordnance."
Locals, who are aware of this issue, have been issuing warnings on various Facebook groups set up to help refugees. One of them urges people to print a map showing where mines are located: “Good maps for printing that can help refugees! Share please,” the post says.
Migration Aid, a civil initiative of volunteers in Hungary helping refugees, has also posted warnings telling people to only use highways and avoid walking across fields.
"Please pay attention. ... Many minefields are not marked ... so tread carefully and stick to clearly visible roads; highway, railway and local roads are totally secure," another Facebook post in both English and Arabic reads.
At least 198 have been killed by mines since 1996 in Croatia, and more than 300 have been injured, according to the Croatian Mine Action Center.
Mine-removal and ordnance-disposal experts are now being sent to eastern Croatia on the border with Serbia, Reuters reported.