Residents said they had been told by police to evacuate their homes in Edmonton following reports of a man with a knife.
Muhammed Yusuf said officers knocked on the door.
He said: "They just said 'You've got to get out of the house'. Of course I was worried."
His son Ahmed,19, said: "At first there were two police cars, then all of a sudden there were 20.
"The police said to drop everything. I said 'What's going on?' and they said there's a guy jumping over gardens."
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