Scary moment Channel 7 reporter is caught in an EARTHQUAKE at the Tokyo Games while reporting from a 10-storey temporary building

Channel Seven sports reporter Mark Beretta has been caught up in a terrifying earthquake scare at the Tokyo Olympics while live on air.

The Sunrise regular was doing an early morning live cross on a 10-storey temporary broadcast tower outside the Olympic stadium in Tokyo when the magnitude-6 tremor struck.

'Welcome back to the Olympic city where we are currently in an earthquake, an earth tremor,' a shocked Beretta told viewers back home.

An earthquake has struck off the coast of Japan causing early morning alarm for Olympians and media in Tokyo

'The roof above us is moving and you might notice our lights and camera are moving as well.'

The tremors continued for another 30 seconds as a rattled Beretta tried to press on with his sports update. 

'That was quite an unusual moment, I have not been through an earthquake before,' he said afterwards.

'That was significant what just happened and it lasted about 30 seconds. 

'The roof started to move on top and I thought, I am having a twisties gymnastics moment! It was unreal. 

Sports report Mark Beretta was doing a live television cross for Sunrise at the time

'And the light started to rock back and forth so that is an earth tremor in Tokyo and they have significant ones so we will get used to it.'

Sunrise co-host Natalie Barr quipped: 'The first time the earth has moved for Beretts.'

The earthquake struck at about 5.30am local time, which is one hour behind AEST.

Numerous aftershocks have been reported but there was no risk of a tsunami or any damage.

Japan, which overlaps four continental plates, is one of the most earthquake-prone countries in the world, with around 5,000 recorded tremors and quakes per year.