A 12-year-old girl has been accused of threatening her school after posting emojis depicting a knife, bomb and gun on social media.

The girl, from Fairfax in Virginia, was arrested after she posted a message on Instagram in December reading "meet me in the library Tuesday" along with emojis of a gun, bomb and knife and the word "killing".

According to the Washington Post, a resource officer at Sidney Lainer Middle School reported the post to police.

When police traced the IP address, it led them to a 12-year-old student of the school.

According to reports, the girl admitted she had published the posts under the name of another student and was charged with threatening the school and computer harassment.

The threat was regarded as "not credible", according to a spokesperson for the school.

This is the latest case in the USA where emojis and emoticons have led to criminal charges.

A grand jury in New York recently had to assess whether the symbols of a police officer and a gun was a credible threat to officers.

A judge in Michigan and even the Supreme Court have been asked to interpret cartoon icons in texts and social media to assess their meaning and whether they could be deemed a threat.