Greta Thunberg attends at Fridays For Future demo

Swedish environmental activist Greta Thunberg on Friday joined tens of thousands of youth in Hamburg to urge politicians, business leaders and everyone else to do more to tackle climate change.

"Our leaders don't seem to understand that the climate crisis is here and now, not something in a far away, distant future," Thunberg said as she gave a speech at the Fridays for Future march.

"We need to see real action - right now," she added.

Thunberg also expressed sympathy over recent events in the German city of Hanau, were nine people were killed by a gunman earlier in the week.