He added: “It would not be appropriate for me to comment on an ongoing police investigation, but the police know how seriously I take this issue and I am confident they will thoroughly investigate the events of July 3.
“I will continue to work closely with the Commissioner to make sure reports of this kind are taken very seriously.”
Simon Johnson, CEO of the Jewish Leadership Council welcomed Mr Khan's assurances.
"[This] is an encouraging first step that we hope will result in the end of the practice," he said. "As I expressed at the time, we were shocked that members of the public can wave the flag of a recognised terrorist group on the streets of London. We will continue to work with relevant officials to ensure that this issue is properly addressed both in London and across the UK.”
