The world's fastest-growing religion is ...

By Daniel Burke, CNN Religion Editor

Updated 2328 GMT (0728 HKT) April 3, 2015

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The annual Hajj pilgramage draws more than 2 million Muslim pilgrims from around the world.
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Managing the crowds at the Hajj – The annual Hajj pilgramage draws more than 2 million Muslim pilgrims from around the world.
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Handling a crowd of that magnitude hasn't always been easy, especially in light of public health scares and terrorism threats. To accomplish such a feat goes off without a hitch, Saudi has had to go high-tech.
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Managing the crowds at the Hajj – Handling a crowd of that magnitude hasn't always been easy, especially in light of public health scares and terrorism threats. To accomplish such a feat goes off without a hitch, Saudi has had to go high-tech.
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Saudi officials have long employed live crowd analytics software CrowdVision to manage the throng with real-time data.
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Managing the crowds at the Hajj – Saudi officials have long employed live crowd analytics software CrowdVision to manage the throng with real-time data.
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While various health crises -- namely MERS and Ebola -- have cast a shadow over this year's proceedings, organizers employed a medical army to address any health issues that might arise.
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Managing the crowds at the Hajj – While various health crises -- namely MERS and Ebola -- have cast a shadow over this year's proceedings, organizers employed a medical army to address any health issues that might arise.
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According to the World Health Organization (WHO), this year there were 180 ambulances on standby, as well as 22,000 health care professionals, 141 health centers, 25 hospitals with 5,250 beds, and 19,000 units of varying blood types.
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Managing the crowds at the Hajj – According to the World Health Organization (WHO), this year there were 180 ambulances on standby, as well as 22,000 health care professionals, 141 health centers, 25 hospitals with 5,250 beds, and 19,000 units of varying blood types.
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Traffic used to be a much bigger problem around the holy sites. Authorities have 15,000 buses on standby. A metro line completed in 2011 has helped to take some of the burden off the roads.
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Managing the crowds at the Hajj – Traffic used to be a much bigger problem around the holy sites. Authorities have 15,000 buses on standby. A metro line completed in 2011 has helped to take some of the burden off the roads.
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To safeguard against the possibility of a terrorist attack, officials installed thousands of CCTV cameras throughout Saudi Arabia, focusing on the holy sites, and employed facial recognition technology.
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Managing the crowds at the Hajj – To safeguard against the possibility of a terrorist attack, officials installed thousands of CCTV cameras throughout Saudi Arabia, focusing on the holy sites, and employed facial recognition technology.
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