British police have made a seventh arrest in the case of a suspected plot against RAF Fairford, an air base in England used by American bombers. Counter Terrorism Policing said a 22-year-old British man was held Tuesday in the Westminster area of London on suspicion of preparing terrorist acts. Officers also searched a property there. No one has been charged.

The arrest came two days after the U.S. emptied the base. A Pentagon official confirmed Sunday that all U.S. bombers at Fairford, thought to be about a dozen B-1s, had flown home. U.S. officials told The New York Times and Reuters that commanders acted on new word of a possible drone attack ordered by Iran's Revolutionary Guard. Some planes left while refueling tankers were still being sent to support their flights, the Times reported.

President Donald Trump said Monday that "there were some threats" and that the people behind them "would be linked to Iran." Vice President JD Vance said the bombers moved "out of an abundance of caution." Secretary of State Marco Rubio would not tie the move to the arrests. A U.S. European Command spokesperson said it would be "inappropriate to discuss matters of intelligence."

Iran denies any role. Its embassy in London called the claims "fabricated speculations," the New York Post reported Sunday. The Post, citing The Wall Street Journal, also said a senior U.S. official claimed the men were recruited by the Revolutionary Guard.

The case began before dawn on Sept. 27. Five British men, ages 23 to 25, were arrested after three white vans were spotted near the base. Homes in the nearby village of Whelford were cleared. Police found petrol in the vans but no explosives, and all five were freed on bail. A sixth man, a 25-year-old who holds British and Iranian citizenship, was arrested Oct. 1 and later bailed. Prime Minister Andy Burnham has said there are "strong indications" that Iran played a part.

Downing Street says the base is safe. A Liberal Democrat defense spokesman called the pullout "deeply concerning," the BBC reported. Some villagers told the BBC they were glad the loud jets were gone.

Fairford, in the Cotswolds, has hosted U.S. bombers for decades. This year it has been a launch point for U.S. strikes on Iran, which Britain allowed only for what it called defensive missions. In July, Iran warned that any base used to attack its land was a "legitimate target."

What we know: The bombers are gone, and seven men have been arrested.
What we don't: What, if anything, the men planned, and whether Iran was behind it.