Image copyright AFP Image caption The castle, before and after October's fire

An appeal has been launched to collect a million images so a famous Japanese castle destroyed in a fire can be "rebuilt" online.

The main structures of Shuri Castle, on the southern island of Okinawa, were burned to the ground in October, despite efforts to save it.

Now an international group of volunteers is hoping to reconstruct the Unesco World Heritage site.

"Our Shurijo" wants to create a virtual 3D model, using videos and photos.

But in order the create the best model, the group needs as many images as possible - and so launched an appeal for people to send in their pictures.

By 30 December, a week after it unveiled an initial model on Twitter, more than 30,000 images had been collected from almost 3,000 people around the world.

Skip Twitter post by @our_shurijo We've digitally reconstructed Seiden of Shuri Castle from collected photos and here is the model!

We're impressed by the detail of the model.

We really appreciate your cooperation.

Take a look at the model and enjoy VR from the link below!https://t.co/Qovl0szafl#OUR_Shurijo pic.twitter.com/16ma207Vyp — OUR Shurijo: みんなの首里城デジタル復元プロジェクト (@our_shurijo) December 24, 2019 Report

But Rei Kawakami, a lecturer at the University of Tokyo's Graduate School of Information Science and Technology, who is leading the project, says the group is hoping for many more.

"We set one million images as our goal because the more we use for the 3D castle, the higher the quality," she told the Kyodo news agency.

What happened to Shuri Castle?

A fire ripped through the wooden castle in the early hours of 31 October.

More than 100 firefighters battled for hours to put the flames out, but they struggled due to high winds.

Media playback is unsupported on your device Media caption These aerial shots show the massive fire consuming Shuri Castle

By the time the fire had been extinguished, the seven main structures had been razed.

However, most of the buildings were themselves a reconstruction: according to Okinawa's tourism site, the castle burned down three times during the Ryukyu Dynasty and was again destroyed in World War Two during the Battle of Okinawa.

The structure which burned down in October had only been open to the public since 1992, following a lengthy project to reconstruct it.

Plans are in place to begin rebuilding the castle once more, but it is unclear how long it will take - and so the international team behind the online model are hoping their version may fill a hole in the community.

"I hope our project encourages local people and gives them the energy to move forward," Ms Kawakami told Kyodo.