Reuters – Interpol said on Wednesday it has issued international wanted-person alerts for two former FIFA officials including Jack Warner and four corporate executives at the request of U.S. authorities as part of a corruption probe.

Interpol said it issued so-called red notices – not an international arrest warrant – for Warner, former President of CONCACAF, which governs soccer in North and Central America and the Caribbean, and Nicolas Leoz, the former head of South America's soccer federation.

The others are Alejandro Burzaco, Hugo Jinkis and Mariano Jinkis, who are among soccer officials and sports media and promotion executives hit with U.S. graft charges involving more than $150 million in bribes, and Jose Margulies, a Brazilian citizen who headed two offshore companies that were involved in the broadcasting of soccer matches.

The move comes one week after the world's most popular sport was rocked by U.S. corruption charges and a criminal investigation into the awarding of the next two World Cups.

REFORM AT FIFA

Sepp Blatter's shock resignation as FIFA president, hours before it emerged he was under investigation by U.S. authorities, prompted widespread calls for root-and-branch reforms at soccer's world governing body on Wednesday.

The Swiss national, 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. An FBI spokesman declined comment.

News of Blatter's investigation was earlier reported by The New York Times and ABC News. Blatter has not been charged with any wrongdoing. FIFA did not respond to a request for comment on Blatter being under investigation.

Blatter, 79, announced his decision to step down at a news conference in Zurich on Tuesday, just four days after he was re-elected to a fifth term as president.

"FIFA needs profound restructuring," he said. "I decided to stand again to be elected because I was convinced it was the best option for football. Although the members of FIFA gave me a new mandate, this mandate does not seem to be supported by everyone in the world."

He said an election to choose a new president would be held as soon as possible, though a FIFA official said it would probably not take place until at least December. Blatter will remain in his position until a successor is chosen.

His daughter, Corinne Blatter-Andenmatten, told a Swiss newspaper her father's decision to stand down was not tied to recent corruption allegations. "His decision has nothing, absolutely nothing, to do with the allegations going around," she told daily Blick.

NOW TIME FOR REFORMS

European sports officials said Blatter's resignation, with FIFA mired in the worst crisis in its 111-year history, was an important step, but that the organization needed deeper changes.

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

New Zealand Football (NZF) 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. "We now want a strong collaborative leader who can bring the football world together and can bring out the change that the game has been crying out for."

The Asian Football Confederation (AFC), which has been a staunch ally of Blatter, said it was monitoring the situation and 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. Indeed, deliberate focus on more governance reform and transparency is now called for."

QATAR FEARS

FIFA was stunned last week by the announcement of a U.S. investigation into alleged widespread financial wrongdoing stretching back more than two decades. Swiss authorities also launched their own criminal probe into the awarding of the 2018 and 2022 World Cups to Russia and Qatar, respectively.

As Blatter signaled 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. "If I was the Qatari organizers I wouldn't sleep very well tonight," he told British media.

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 tumbled as much as 3 percent to a 6-week low in early Wednesday trade amid heightened investor fears that Qatar could be stripped of its hosting rights.