Karachi has secured a slot among the top 60 safest cities in The Economist Intelligence Unit's The Safe Cities Index 2017 , but the one at the very bottom.Pakistan financial hub ranked 60th with an overall score of 38.77.It ranked last for health security and personal security, and had the highest frequency and severity of terrorist attacks.Tokyo tops the overall ranking, scoring 89.8, with its strongest performance is in the digital security category while it has risen seven points in the health security category since 2015. However, in infrastructure security, it has fallen out of the top ten, to 12th.Singapore received a score of 89.64, and Osaka 88.87. Toronto, Melbourne, Amsterdam, Sydney, Stockholm, Hong Kong, and Zurich also made it to the top 10.Yangon in Myanmar came in second last with a score of 46.47. Dhaka, Jakarta, Ho Chi Minh City, Manila, Caracas, Quito, Tehran, Cairo, and Johannesburg were also at the bottom of the list.The US performed well in digital security, but the country's infrastructure negatively affected its rankings this year. No US city was among the top 10 - San Francisco, at 15, was the only one in the top 20.It is observed in the report that in many cities, security is falling rather than risingWith two exceptions (Madrid, which is up 13 points and Seoul, up six), cities tend to have fallen in the index since 2015 (for example, New York is down 11, Lima is down 13, Johannesburg is down nine, Ho Chi Minh City is down ten and Jakarta is down 13.Asian and European cities remain at the top of the indexOf the cities in the top ten positions in the overall index, four are East Asian cities (Tokyo, Singapore, Osaka and Hong Kong), while three (Amsterdam, Stockholm and Zurich) are European.Asia and the Middle East and Africa dominate the bottom of the index.Dhaka, Yangon and Karachi are at the bottom of the list. Of the 10 cities at the bottom of the overall index, three are in South-east Asia (Manila, Ho Chi Minh City and Jakarta), two are in South Asia (Dhaka and Karachi) and two are in the Middle East and Africa (Cairo and Tehran).Security remains closely linked to wealth but the scores of high-income cities are falling. While cities in developed economies dominate the top half of the index (with the lower half dominated by cities in poorer countries), of the 14 cities in high-income countries, the security scores of 10 have fallen since 2015.Income is not the only factor governing city performance on security:.Most of the cities in the top ten of the index are high-income or upper middle-income cities. However, two high-income cities in the Middle East (Jeddah and Riyadh) fall below position 40 in the index.The report is based on the second iteration of the index, which ranks 60 cities across 49 indicators covering digital security, health security, infrastructure security and personal security.