Law enforcement officials made more arrests on Thursday in the ongoing investigation of soccer's world governing body Fifa, at least some of them in a pre-dawn raid on a hotel in Zurich, Swiss authorities and the New York Times said.

Authorities were targeting current and former senior soccer officials on charges that included racketeering, money laundering and fraud, the New York Times said.

Zurich police, asked by Reuters about more arrests in the Fifa case, said they took action at the request of Swiss federal justice authorities, but gave no other details.

The Baur au Lac hotel in Zurich closed its gates after a group of four people, believed to be plainclothes police, went in shortly before 6 am, a Reuters witness said. Another group of police then went in through the rear entrance and left half an hour later.

Shortly afterwards, two cars with tinted windows were seen leaving the hotel. Reporters could not see who was inside.

Fifa said it was aware of the arrests but did not give details.

"Fifa became aware of the actions taken today by the US Department of Justice. Fifa will continue to cooperate fully with the US investigation as permitted by Swiss law, as well as with the investigation being led by the Swiss Office of the Attorney General," a statement said.

Authorities have said for months to expect a second wave of corruption charges in soccer following US charges in May against 14 officials and sports marketing executives with paying and taking bribes.

US Department of Justice officials were expected to appear at a news conference in Washington as soon as Thursday to discuss the case, people familiar with the plans said.

PARALLEL PROBES

Swiss and US authorities are conducting parallel investigations of corruption in soccer, focusing on whether certain business contracts or the World Cup hosting rights for 2018 and 2022 were won with the help of bribery.

The leaderships of several South American national soccer organizations have been upended. Last week, Marco Polo Del Nero, the head of the Brazilian Football Confederation, resigned his post on FIFA's executive committee amid criticism of his leadership.

Also last month, the president of the Colombian Football Federation, Luis Bedoya, resigned unexpectedly as a government source said Bedoya had flown to New York. The president of Chile's ANFP national football association, Sergio Jadue, resigned his post and went to the United States to talk to the FBI, Chilean media reported.

The US and Swiss investigations have breathed new life into efforts to overhaul Fifa. A reform committee is expected to present recommendations on Thursday to Fifa's executive committee at a meeting in Zurich, where Fifa has its headquarters.

On Tuesday, leading FIFA sponsors Anheuser-Busch InBev NV, Adidas, The Coca-Cola Company, McDonald's Corp and Visa Inc published an open letter demanding independent oversight of the reform process. - Reuters