The bikers smashed the windows and left with watches and jewellery.
They made their way towards Hendon Central and abandoned their bikes afterwards at a golf course.
No one was injured in the robbery except an pensioner, who was treated for shock at the scene.
The raid happened at 10.15am, only quarter of an hour after the mall opened for shopping.
“We looked out and we saw six men, two on each bike, pull up outside Fraser Hart,” said eye-witness Claire Smalley to the BBC,
“and then they pulled out an axe and they were getting into Fraser Hart and telling everyone to stay back.”
It’s believed that the robbers went straight for the Cartier and Rolex watches in store.
The police are urging anyone with any information on this crime to contact the police immediately.