Interpol put two top former FIFA officials on its "red notice" wanted list at the request of U.S. authorities on Wednesday as their investigation into corruption at soccer's governing body gathered pace.

The move by the international police body came the day after FIFA President Sepp Blatter stunned world soccer by resigning shortly before it emerged that he was also under investigation by U.S. law enforcement.

A source close to FIFA said Blatter's advisers had told him he must reverse course and quit. Critics pointed to the widening criminal probe, disquiet among sponsors, and pressure from Europe's powerful soccer body UEFA as possible reasons.

With Blatter saying he no longer had the mandate he sought, UEFA postponed a meeting due on Saturday at which there might have been talk of a revolt against FIFA.

UEFA had opposed Blatter, and Michel Platini, the UEFA president who is favourite to succeed the 79-year-old Swiss national, had urged him not to stand for re-election as FIFA faced the worst crisis in its 111-year history.

"Due to yesterday's announcement and the uncertain and unpredictable nature of the investigations, I have decided that it would be more appropriate to postpone the meeting that was announced last week, and which could have taken place in Berlin this weekend," Platini, a former French soccer star, said.

"Considering new information is revealed every day, I believe it is wiser to take time to assess the situation, so together we can take a position on this issue."

As the FIFA crisis unfolds, Interpol issued international wanted person alerts for Jack Warner, former president of Concacaf, which governs football in North and Central America and the Caribbean, and Nicolas Leoz, the former head of South America's soccer federation.

The others subject to the so-called "red notices" - not arrest warrants - are Alejandro Burzaco, Hugo Jinkis and Mariano Jinkis, who are among soccer officials and sports media and promotion executives facing U.S. corruption charges involving more than $150 million in bribes, and Jose Margulies, a Brazilian who headed two offshore companies that were involved in broadcasting soccer matches.

FIFA has denied that another senior official, Secretary-General Jerome Valcke, was involved in a $10 million payment approved by the South African Football Association that lies at the heart of the U.S. investigation.

At a news conference in Johannesburg, sports minister Fikile Mbalula denied that the payment to Warner during South Africa's successful bid for the 2010 World Cup was a bribe.

Mbalula said South Africa had not bought votes for the right to host the finals.

U.S. legal authorities last week announced they are investigating alleged bribery and corruption at FIFA going back 24 years and Swiss prosecutors announced their own criminal investigation into the award of the 2018 World Cup to Russia and the 2022 tournament to Qatar.

The Kremlin said Russia was surprised by Blatter's resignation but was pressing on with preparations for the World Cup finals in 2018.

Blatter, who has led FIFA for 17 years, is being investigated by U.S. prosecutors and the Federal Bureau of Investigation, a person who spoke on condition of anonymity told Reuters late on Tuesday.

U.S. Attorney General Loretta Lynch, on a visit to Latvia, declined to comment on whether Blatter is under investigation.

Blatter has not been charged with wrongdoing. FIFA did not respond to a request for comment on Blatter being under investigation.

Blatter announced his decision to step down at a news conference in Zurich on Tuesday, six days after police raided a hotel in the city and arrested several FIFA officials - and just four days after he was re-elected to a fifth term as president.

An election to choose a new president will probably not take place until at least December. Blatter, meanwhile, remains in his position.

His daughter, Corinne Blatter-Andenmatten, told a Swiss newspaper her father's decision had "absolutely nothing" to do with recent corruption allegations.

European sports officials said Blatter's resignation was an important step, but that the organisation needed deeper changes.

"Beyond the people, structural reforms must be undertaken," said French Sports State Secretary Thierry Braillard.

New Zealand Football Chief Executive Andy Martin said soccer must now rebuild its tattered reputation.

"This has lifted a cloud and taken away a lot of the concerns of stakeholders and their association with the sport," he told Reuters.

The Asian Football Confederation (AFC), which has been a staunch ally of Blatter, said it would discuss internally the "best way forward for both FIFA and world football".

AFC member the Philippines Football Federation said it was surprised by Blatter's decision, but noted this "offers a big opportunity to continue and intensify the reforms that have been started".

As Blatter announced his exit, English Football Association Chairman Greg Dyke raised the possibility that the controversial vote that awarded Qatar the 2022 tournament could be re-run.

Qatar Football Association President Sheikh Hamad Bin Khalifa Bin Ahmed Al-Thani hit back, indicating the small Gulf state will not give up hosting soccer's showpiece event without a fight. "We would urge Mr Dyke to let the legal process take its course and concentrate on delivering his promise to build an England team capable of winning the 2022 World Cup in Qatar," he said.

Qatar's stock index fell as much as 3 percent to a 6-week low amid fears Qatar could lose the World Cup.

Among the potential candidates to lead FIFA, Platini, is the favourite.

Jordan's Prince Ali Bin Al Hussein, who withdrew from last week's presidential election after winning 73 votes to Blatter's 133 in the first round, stopped short of confirming he would run again. Asked if there should be a fresh start at FIFA, he told Britain's Channel 4 News: "I'm willing to help."

Chung Mong-joon, billionaire scion of South Korea's Hyundai conglomerate, said he would "carefully consider" running.

Other possible candidates include Domenico Scala, independent chairman of FIFA's audit and compliance committee.

Former Brazil international Zico, 62, did not rule out a bid, and Venezuelan President Nicolas Maduro proposed Argentine soccer legend Diego Maradona.

Others include Jerome Champagne, a former French diplomat and FIFA deputy secretary general, and German Wolfgang Niersbach, a former sports journalist and FIFA media chief.-Reuters