Fearing that safety could be compromised due to damage caused to the tyres by the kerbs at the Lusail circuit, the FIA has announced a number of measures.

The standard analysis of tyres used during Free Practice 1, in which tyres that have been used for approximately 20 laps are examined by Pirelli to check various safety parameters, a separation in the sidewall between the topping compound and the carcass cords on many of tyres that were checked was discovered.

It is the view of the FIA and Pirelli that a significant number of additional laps on these tyres could result in circumferential damage of the tyres with subsequent air loss, and tyres analysed with lower lap numbers showed a much-reduced extent of the issue.

This issue has likely been caused by the high-frequency interference between the tyre sidewall and the 50mm 'pyramid' kerbs used extensively at the circuit, aggravated by the propensity to ride those kerbs.

The following actions will be taken on safety grounds in response to this issue:

Track limits at Turns 12-13 will be revised.

There will be a 10-minute Practice Familiarisation Session, scheduled to start at 16:00 local time, following the revision of the track limits, to allow drivers to adjust to the changes. The Sprint Shootout will therefore start 20 minutes later than scheduled (16:20 local time).

There will extensive tyre analysis following the Sprint (19 laps), to decide whether further action needs to be taken ahead of the Grand Prix.

In the event the problem is still evident, we will be issuing the following directive for Sunday's Grand Prix, on safety grounds:

The tyre life parameter must not exceed 20 for new tyres used in the race. This number would rise to 22 for any used tyres fitted in the race, to account for in-out laps in qualifying.

All drivers will be obliged to perform at least three tyre-change pit stops during the race.

Pirelli and the FIA will carry out extensive research and simulations in order to establish with complete confidence the reasons behind this issue, and to work on solutions to avoid it in the future.

The move sparks memories of the infamous United States Grand Prix at Indianapolis in 2005 when none of the Michelin-shod teams started the races over tyre safety concerns, and comes after Yuki Tsunoda fears that the kerbs would prove to be tyre "destroyers".

"There is always a story with track limits," said the AlphaTauri driver on Thursday, "but they made even worse the kerbs because when you go over the white line, you are going to have a proper penalty, which seems like it's going to be a high risk to damage the car. It seems like they changed to the aggressive kerbs."

Check out our Saturday gallery from Lusail here.