There have been more sightings of the B-2 Spirit aircraft this week, as they take part in exercises from an airfield in the UK.
Three of the warplanes have been deployed to RAF Fairford, Glos, from where they have been flying training sorties.
They have included flights with F-35 Lightning jets from RAF Marham over the white cliffs of Dover.
The aircraft have also been joined by flying tankers from RAF Mildenhall, in Suffolk, which refuelled them during a sortie over the Norwegian Sea.
On Wednesday one of the aircraft was sighted over the outskirts of Norwich and near Ipswich, on an as-yet undisclosed mission.
The US Air Force has not yet revealed how long the aircraft will be based in the UK.
One senior officer said the deployment provided "an opportunity to train and integrate with our allies and partners in the region".
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