Clubs have ensured fans that extra precautions have been taken to mitigate any potential attacks, including the beefing up of security at the four stadiums where fixtures will be played.
According to Sky News, the threats were originally shared by the Al Azaim Foundation, which has on numerous occasions helped disseminate ISIS' messages. The post named all four stadiums and claimed that the terrorist group wanted to "kill them all."
When the threats were brought to the attention of UEFA, the Champions League's governing body assessed them and gave the go-ahead to proceed.
"UEFA is aware of alleged terrorist threats made towards this week's UEFA Champions League matches and is closely liaising with the authorities at the respective venues," officials said in a statement. "All matches are planned to go ahead as scheduled with appropriate security arrangements in place."
Two matches are set to be played Tuesday night, with Arsenal taking on Bayern München at home at Emirates Stadium and Manchester City traveling to play Real Madrid in the Spanish capital.The Metropolitan Police said there was a "robust policing plan" in place for the game in north London, and Gunners' executives noted that they were "working closely" with law enforcement. In a statement, the club said its response to the situation was "proportionate to the current UK threat level."
Meanwhile in Madrid, authorities there have opted to keep the roof of the Santiago Bernabeu Stadium closed as a precaution.
The other two matches are scheduled for Wednesday night, with Paris Saint-Germain taking on Barcelona in the French capital and Borrusia Dortmund traveling to Spain to play Atletico Madrid at the Metropolitano Stadium.
