PHILADELPHIA (Reuters) - Democratic presidential candidates Joe Biden and Bernie Sanders canceled primary election-night rallies on Tuesday, bowing to guidance from public officials over the coronavirus outbreak, and the party said the next debate between the two would have no audience.

The dueling rallies - the first major U.S. campaign events to be canceled because of the outbreak - had both been scheduled for Cleveland, Ohio.

Ohio, Florida, Illinois and Arizona next week will hold their primaries in the race to nominate a Democratic challenger to Republican President Donald Trump in November. Six states, including Michigan and Washington, held their contests on Tuesday.

The Democratic race has narrowed to a two-way battle between Biden, the former vice president running as a moderate, and Sanders, a senator from Vermont and a self-described democratic socialist.

Both candidates have criticized the Trump administration over its response to the outbreak in the United States of coronavirus, which causes a highly contagious and sometimes fatal respiratory illness known as COVID-19.

Their campaigns said they would consult with health officials about future events.

Trump has sought to play down the extent of the threat and has held several rallies in recent weeks aimed at stealing the spotlight from the Democrats. On Tuesday his campaign said he would hold a “Catholics for Trump” event in Milwaukee, Wisconsin, on March 19.

Democratic U.S. presidential candidate and former Vice President Joe Biden reboards his campaign plane with his wife Jill shortly after landing in Cleveland to depart after cancelling a primary night rally over coronavirus concerns in Cleveland, Ohio, U.S., March 10, 2020. REUTERS/Brendan McDermid

Kate Bedingfield, Biden’s communications director, said the Cleveland rally had been canceled “in accordance with guidance from public officials and out of an abundance of caution” hours after Ohio Governor Mike DeWine called for all large-scale indoor gatherings to be avoided.

Biden planned instead to speak to reporters in Philadelphia, where he also was expected to talk about the coronavirus crisis.

“We are heeding the public warnings from Ohio state officials, who have communicated concern about holding large, indoor events during the coronavirus outbreak,” Mike Casca, the Sanders campaign communications director, said in a statement.

As coronavirus fears spread, voters in Michigan said they trusted Biden more than Sanders to handle a major crisis, according to exit polls on Tuesday.

The Democratic National Committee added that its next presidential nominating debate in Arizona on Sunday would not have a live audience because of the health concerns.

Biden’s campaign also canceled a get-out-the-vote event scheduled for Wednesday in Tampa, Florida.

The COVID-19 disease has so far sickened almost 1,000 people in the United States and killed 29, mostly in Washington state. Washington was also conducting its primary on Tuesday, although voting in that contest occurs by mail.

While the outbreak has shaken financial markets, forced school closures and prompted organizers to cancel concerts, conferences and sporting events, the candidates until now have largely pressed on as usual, holding events and shaking hands.

Journalists asked Vice President Mike Pence at a news briefing on Tuesday if the Trump campaign’s plans were changing in light of the health crisis.

“That’ll be a decision that’s made literally on a day-by-day basis,” Pence said. “I’m very confident that the campaign will take the very best information and make the very best decision going forward.”