American Chinooks have been spotted flying over London during Wednesday's Nato summit attended by US President Donald Trump.
The military aircraft were mostly seen in the skies above north London with many city dwellers complaining of the noise.
While some said the circling helicopters woke them up, others marvelled at the spectacle of seeing the huge aircraft above London.
There has been an increase in sightings of the Boeing CH-47 helicopters since POTUS and other world leaders landed in the city.
They gathered at Buckingham Palace at the invite of the Queen on Tuesday evening, the start of the two-day meeting.
The Nato heads of state have now met in the Grove Hotel in Hertfordshire where the talks will likely focus on the current tensions in the alliance.
Turkey has said it will oppose a Nato defence plan for Baltic countries.
British Prime Minister Boris Johnson has called for unity and reiterate the importance of the alliance ahead of the UK elections on December 12.
Mr Johnson has stressed the importance of brokering a trade deal with the United States as the country leaved the EU.
However, negotiations have not been helped by Mr Trump's complaints that the European Nato countries are not contributing enough money to the bloc.
Mr Trump takes his seat at the conference as he faces an impeachment process back home in the US
Nato was created as a defence against the post-World War Two communist expansion.
Part of the pledge countries make as members is to come to the aid of one another should any of the 29 allies come under attack.
