"European shares are trading once again lower. continuing their slide on the back of ever more increasing tensions between North Korea and the USA", added analyst Markus Huber at City of London Markets.
The UK blue-chip index closed 113 points, or 1.5%, lower at 7,385, steadily losing ground as the trading session wore on. Investors, meanwhile, are fleeing to more stable investment markets.
The reclusive state raised the stakes further on Thursday with a detailed plan to send a salvo of missiles towards the USA territory of Guam.
A statement attributed to North Korea's head of strategic forces, General Kim Rak Gyom, said the plan for the strike would be ready by the middle of the month and would await orders from leader Kim Jong-un. Secretary of state Rex Tillerson said yesterday North Korea posed no "immediate threat" and that "Americans should sleep well at night, have no concerns about this particular rhetoric of the last few days".
"While not necessary unexpected - as the United States had to respond to threats made by North Korea that they will fire rockets due to land just off the coast of Guam soon - new comments by Trump propelled stocks lower".
'Traders are on red alert as the mention of war has sent them running for cover.
Investors appeared to be moving their money into the relative safety of bond markets.