Security concerns have been raised after a fitness tracking firm showed the exercise routes of military personnel in bases around the world.
Online fitness tracker Strava has published a "heatmap" showing the paths its users log as they run or cycle.
It appears to show the structure of foreign military bases in countries including Syria and Afghanistan as soldiers move around them.
The US military is examining the heatmap.
San Francisco‑based Strava provides an app that uses a mobile phone's GPS to track a subscriber's exercise activity.
It uses the collected data, as well as that from fitness devices such as Fitbit and Jawbone, to enable people to check their own performances and compare them with others.
It says it has 27 million users around the world.
Source: BBC
