Zombie and zebra among new emoji characters previewed by Apple

Apple has used World Emoji Day to preview the range of new characters that will be added to its software later this year.

The technology giant revealed images of a woman with a headscarf as well as new zebra, zombie and smiley face emoji that will become available to users of Apple's mobile devices and desktop computers.

In total, 56 new emoji have been approved by the Unicode Consortium, the non-profit organisation that approves new emoji characters for public use, and they will also appear on Android and Windows devices as well as social media later this year.

The consortium approves the rough images, but companies such as Apple and Google are free to create their own versions of each emoji.

The colourful characters have become a central part of modern digital communication - celebrities including Kim Kardashian and Justin Bieber have launched their own range of personalised icons, while the official Unicode standard now includes more than 2,500 icons.

To mark World Emoji Day, the Royal Opera House in London has been tweeting the plot of famous operas and ballets using only emoji icons, giving away tickets to social media followers who can identify the ballet or opera in question.

World Emoji Day began in 2014, with the date July 17 chosen because it is the date that appears in the "calendar" emoji.