Five British men were arrested on Sunday near a British air base, which is also used by the United States, on suspicion of a planned terrorist attack. They have since been released on bail, but the investigation is still ongoing.
"It's clear that a foreign actor is involved," Rubio told Fox News.
There is a lot of news that will come out about this in the coming days, but I can't say much right now.
US President Donald Trump says the case "may be" linked to Iran, but does not go into any details. Iran has consistently denied any involvement in the incident. The president is critical of the suspects being released on bail.
"I'm surprised they released them, I wouldn't have done it," Trump says, adding that British authorities worked closely with the United States.
"We know everything about them. We wouldn't have let them go."
The five male suspects are between 23 and 25 years old and live in London.
