FLORENCE, Italy (REUTERS) - Spectators at World Cup matches will be able to see replays of incidents which are reviewed by the video assistant referee (VAR) on the stadium screen once a decision has been made, Fifa said on Wednesday (April 18).

Fifa, responding to criticism that fans are often in the dark over the use of the VAR system, said the crowd would also be informed when a decision was being reviewed and why a given decision had been reached, such as a disallowed goal or revoked penalty.

Soccer's rule-making body IFAB approved the use of the VAR system in March and Fifa subsequently confirmed that it would be used at the World Cup in Russia.

The system is already being used on a trial basis in Serie A and the Bundesliga, among other competitions, although its use has led to confusion and there are worries that system is still not working smoothly enough for a big tournament.

"We know communications inside the stadium and outside is important..we are learning the experience of different leagues," IFAB's head of technology Sebastian Runge told reporters.

Runge said a system had been introduced to ensure that the crowd at World Cup matches knew what was happening.

A Fifa member of staff in the video operations room will inform the operator of the stadium screen plus broadcasters and commentators as soon as the referee is in communication with the VAR over a decision If the referee decides to review the incident, that would also be communicated and once the decision is made, it would be announced on the screen with the reason and the incident would be replayed.

"We are not showing any replays while the referee is making the decision, only afterwards," Runge added.

"We don't want the referee to be influenced by the crowd...if we showed what is happening on the screen before the decision, there would be some reaction and it could have an influence." Runge said a breakdown of the VAR system during a match was unlikely.

"The only thing that can really fail is the link between the communications system in the stadium and the system in the International Broadcast Centre in Moscow," he said.

VAR CONFUSION

The use of VARs in leagues has been surrounded by confusion among the fans and even coaching staff.

There have been cases of players in Serie A waiting to take a penalty for several minutes before the referee has reversed the decision and awarded a free kick to their opponents amid general bewilderment.

In others, players have scored goals, the entire stadium has celebrated and the score has flashed across on live scoring websites, only for the incident to be reviewed as the other team is about to re-start the game and the goal annulled.

Pierluigi Collina, the head of Fifa's refereeing committee, said that VAR should only be used to correct obvious mistakes in match-changing incidents.

"The goal of VAR is not to have clear and obvious mistakes committed on the field of play," he said.

"VAR won't provide a final answer. There will continue to be incidents where a final answer cannot be given....the target is to avoid major mistakes, not to scrutinise every single decision."