Voting in the election to lead football's world governing body FIFA will go into a second round after neither incumbent President Sepp Blatter nor Jordanian challenger Prince Ali bin Al Hussein got two-thirds of the vote.

Blatter secured 133 votes and Prince Ali won 73 at FIFA's annual Congress in Switzerland.

The Swiss is expected to be re-elected, defying growing calls for him to step down in the face of corruption scandals.

Two other candidates - Portugal's Luis Figo and Dutch Michael van Praag - withdrew last week.

FIFA reels from arrests of top officials

Addressing delegates at the gathering, Blatter promised more transparency and urged members to remain unified after twin criminal investigations rocked world football's governing body this week.

"It may not always be easy but we are here together today to tackle the problems that have been created. We are here to solve them," Blatter said.

"I think the important point today is to move ahead and the important point is transparency.

"The important point is where does FIFA stand in the world. It is the fight against corruption, against match fixing, racism and discrimination which we still have and this hurts.

"Let's show to the world we are able to run our institution which is FIFA we can do it together."

There was panic during the lunch break when Zurich police moved into the hall following a reported bomb threat.

However, FIFA's secretary-general confirmed that the premises were searched and cleared by the authorities.

Blatter still favourite

Blatter's opening address to the congress on Friday was briefly interrupted by a female protester waving a Palestine flag and shouting at Blatter before being removed.

Blatter, who has been heavily criticised for not doing enough to combat corruption in FIFA, is being challenged by Jordanian Prince Ali bin al-Hussein for the most powerful job in soccer on Friday.

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A number of delegates have told Al Jazeera, however, that they expect Blatter to easily win his job back despite the new corruption inquiries.

Swiss authorities said on Wednesday they had launched a criminal investigation into the bidding contest for the 2018 and 2022 World Cups - set to be held in Russia and Qatar.

Almost simultaneously, the US Department of Justice indicted nine FIFA officials and five associated officials on corruption charges, with Swiss authorities arresting seven of the officials in Zurich where FIFA is holding its congress.

FIFA's 209 members will vote in Friday's elections, with a two-thirds majority needed to win on the first ballot.

If that does not happen, then a straight majority is required to win a second ballot.

Source: Al Jazeera and agencies