Police are investigating a suspected arson attack at a memorial wall in north London. Scotland Yard said the investigation was being led by counter-terrorism policing, but it was not being treated as a terrorist incident. No arrests have yet been made and the memorial wall was not damaged. The memorial wall is a tribute to thousands of protesters killed in a crackdown in Iran in January, and is near a Jewish centre. Ali Vahedi, a volunteer from the Miga Rally community group that set up the memorial and organises security to watch the wall, said: “Last week a drone was here, people come and throw things like tomatoes and now last night, after this fire happened, it is getting more dangerous. We started security here three months ago because we did not feel safe.” At first police thought the fire had been started by a candle, but CCTV footage showed a person using a liquid to try to start a blaze. Vahedi said: “The fire started from the end of the table and it spread everywhere.…