Mount Fuji behind Tokyo
Japan's highest mountain Mount Fuji (top L) rises up behind the skyscrapers dotting the skyline of the Shinjuku area of Tokyo at sunset on 21 October, 2012. KAZUHIRO NOGI/AFP/Getty Images

A new report has named the Japanese capital, Tokyo, as the safest city in the world for the third year running. The Safe Cities Index 2017, developed by The Economist Intelligence Unit, is a report that ranks 60 cities against 49 security indicators.

These indicators include health security and digital security, along with personal security. Tokyo topped the table in digital security, the researchers said, while also rising seven places in health security.

Tokyo did less well in the infrastructure security category, a theme shared with American cities. Only one US city made it in the top 20 for infrastructure: San Francisco.

The report also has a small warning: "In many cities, security is falling rather than rising". Apart from Madrid and Seoul, major cities are dropping in the index since the last iteration in 2015. One major factor, the report posits, is a rapid adoption of the Internet of Things, wireless connections between items all over the city, without first considering the adoption of better cyber security.

Tokyo isn't the only Japanese city to score highly - number three on the overall list is Osaka. In second place is Singapore. London comes way down in 20th place – well beaten by cities like Zurich and Frankfurt, which came 10th and 11th respectively.

At the bottom of the list several of the newly added developing world cities can be found. In 60th place is the Pakistani city of Karachi, which researchers said was dragged down by its low score in personal security, stemming largely from more frequent terrorist attacks.

The two worst performing cities from the developed world were the Saudi Arabian cities of Jeddah and Riyadh, the researchers said, both dragged down by poor scores in infrastructure and personal security. The highest performing Middle Eastern city was Abu Dhabi in 28th place, followed closely by Doha, Qatar, in 30th.