IAEA-led team was fanning out in western Georgia in search of the remaining two of a batch of eight abandoned devices containing strontium-90, another radioactive element, which had been used in generators for communication stations.

ECONOMIST: How dirty bombs are made, and what they can do

However, it has added a further element to the referee's pre-match ritual with officials now needing to test the system 90 minutes before every match to determine whether the technology is working as expected.

CNN: World football enters technological era