The Ministry of Defence says it is coordinating with all relevant parties and that the situation is now resolved.
Nick Timothy, the MP for West Suffolk, says he was told the incident is resolved and there is no danger to anyone nearby.
That's everything we know.
Why this mattersSo let's talk about what RAF Lakenheath actually is.
It's not a small base. It hosts the US Air Force's 48th Fighter Wing. That's the biggest American fighter operation in Europe. Nearly 7,000 troops are based there. It flies F-15E Strike Eagles and F-35A Lightning IIs.
So a drone over that base gets taken seriously. Real or not.
And here's the thing. This has been a strange week for bases nearby.
Four days ago, KC-135 Stratotanker refuelling planes based at RAF Mildenhall were sent out to Prestwick, Spangdahlem, Ramstein and Morón. CV-22B Ospreys came the other way, into RAF Lakenheath. At least 12 US Air Force aircraft left Mildenhall this week in total.
Lakenheath and Mildenhall had already raised their protection level to FPCON Charlie earlier this week. Nobody said why at the time. Unconfirmed reports tonight say Lakenheath, Mildenhall and RAF Feltwell have gone further, to FPCON Delta. That's the highest protection level there is. It has not been officially confirmed.
So why move the tankers?
The Wall Street Journal says it was a threat from Iran. The BBC has not independently verified that. A US official says the move was proactive, not a reaction to one specific attack.
And here's why Iran is the name in the room.
Two months ago, something happened at RAF Fairford, another US base in England. Prime Minister Andy Burnham has said Iran played a part in it. Police searched vans nearby and found petrol. Not explosives. The US pulled all its B-1 bombers out of Fairford the next month.
Since then, the case has moved fast.
The Crown Prosecution Service has charged two men over the Fairford incident. Prosecutors say one of them tried to assist Iranian intelligence in Britain. This week, the US Justice Department separately charged three men it calls Iranian operatives, over an alleged plot at the same base.
Iran denies all of it. Tehran rejects any involvement in Fairford or in other alleged activity in Britain.
Britain's domestic spy chief said last month that Iran has been stepping up attempts to hit harder targets. That includes military sites on British soil.
Downing Street said earlier this week that British airbases are safe, and that their security is a top priority.
But nobody has said tonight's drone is connected to any of that. Not the US Air Force. Not the Ministry of Defence.
So what don't we know? Almost everything about the drone itself. How many there were. What type. Where exactly it was seen. Whether it was recovered. Who was flying it.
For now, the base says the threat has passed.
Whether it was ever more than a drone is still the open question.
