I was driving near Harefield (North West London) at about 3pm today (11th), and through the trees in the distance I could see a 757 (possibly) with two jets escorting it heading East, possibly tracking the route of the A40. It was North of Heathrow and maybe heading to Northolt. There was no landing gear down. I would also say that it was at about 4000 feet. Due to the trees along the road and the fact that I was driving, meant I couldn't get a proper look.
Any idea what this was? I don't believe it had anything to do with the Lord Mayor's Show this morning or with the Remembrance Day events, but I may be wrong. The only conclusion I had was that it could be an American visitor.