Coronavirus pandemic

The shows were held at secret locations, each lasting five minutes from 20:00 local time (12:00 BST).

Organisers set a time limit for the displays to avoid crowds gathering.

Initially, they said the time and date of the event would not be revealed but later reversed course, deciding a sudden pyrotechnics show could cause distress to some.

Filling the skies with a burst of light, the fireworks lasted long enough for people who did not know about it in advance to view them from the street or their homes.

The tech firm will publish details of the different types of places people are going to on a county-by-county basis in the UK, as well as similar data for 130 other countries.

The plan is to issue a regular updates with the figures referring back to activity from two or three days prior.

The company has promised that individuals' privacy will be preserved.

The readings are based on location data gathered via the Google Maps app or one of the firm's other mobile services.

It took 67 days from the first reported of Covid-19 to reach 100,000 cases, 11 days for the second 100,000, and just four days for the third 100,000.

But WHO Director General Tedros Adhanom Ghebreyesus said it was still possible to "change the trajectory".

He urged countries to adopt rigorous testing and contact-tracing strategies.