This year, it's drones featuring thermal imaging and robots handing out religious advice.A decade ago, it was all about the miracle of the mobile phone. And a century or so ago, the motor car was the highest of high-tech used during the annual Hajj pilgrimage.

The Hajj, one of the largest gatherings of humans on Earth, is meant to be undertaken by every adult Muslim once in their lifetime. It will begin in Saudi Arabia on June 4 and end June 9. During those days, up to 2 million pilgrims from over 180 countries will take part in a number of different religious ceremonies in Mecca.

But having so many people moving around in one comparatively small area has led to problems in the past. Thousands of pilgrims were killed in stampeding crowds in 1990 and 2015. Last year over 1,300 died due to extreme heat; pilgrims often walk up to 65 kilometers a day in 40-to-50 degrees Celsius heat. There have also been fires, protests, suicides, collapsing buildings and infectious diseases at the Hajj, as well as more everyday problems like people getting lost or having health problems.

No wonder then that the Saudi authorities are trying to use technology to improve how they control crowds and cater to their visitors. This year, Saudi Arabia will use drones with thermal imaging as well as artificial intelligence and facial recognition technology to ensure that only those who have Hajj permits are allowed in.

Last year's many deaths were mostly of pilgrims who didn't have official permission to be there and........

© Deutsche Welle