How is India managing its Maha Kumbh, the world's largest gathering?

Maha Kumbh is set to be the world's largest gathering of humanity, with 400 million visitors expected at the six-week event that began on Monday in Prayagraj.

Here is a look at how authorities are managing the mammoth crowds at the festival.

Tent city

A temporary city has sprung up across 4,000 hectares (9,990 acres) on the river banks, with 150,000 tents to accommodate devotees and almost an equal number of toilets.

About 69,000 LED and solar lights light up the paths through the settlement, kept clean by 15,000 sanitation workers.

Security

Temporary police stations and checkpoints in Prayagraj include three floating 'water police stations' on the river, while paramilitary troops and bomb disposal squads are also at the ready.

More than 50,000 personnel are on guard to ensure the safety of visitors.

Technology

Authorities are using closed circuit television (CCTV) cameras, drones, and tethered drones to monitor the festival area, along with anti-drone craft to find and remove unauthorised drones.

Also in use are underwater drones that can operate in a depth of 100 metres (3,330 ft), equipped with advanced technology to function in low-light conditions.

Fire safety

Every tent has been fitted with fire-fighting equipment, while more than 1.3 billion rupees ($15 million) has designated for fire safety in the festival area, with 351 firefighting vehicles and 2,000 trained personnel on hand to immediately stamp out any fires.

Lost-and-found centres

To help reunite families separated in the crowd, centres with dedicated sections for women and children have been set up, while loudspeakers installed along the river banks will make continuous announcements about those separated.