WASHINGTON: Five US states held primaries on Tuesday for November’s presidential election, in a crucial round that could give Democrat and Republican front-runners a chance to cement their leads. Polls have opened in Ohio and Florida as well as in North Carolina, Illinois and Missouri.

Trump entered the voting embroiled in one of the biggest controversies of his contentious campaign. The billionaire real estate baron urged supporters to physically confront protesters at his campaign events and now faces criticism for encouraging violence after skirmishes broke out at a rally last week in Chicago.

During an event Monday in Florida, Trump was interrupted by protesters. Some were forcibly removed. Trump said he didn’t want to “ruin somebody’s life, but do we prosecute somebody like that?“

Florida and Ohio were the biggest prizes Tuesday, but Missouri, Illinois and North Carolina also awarded a large cache of delegates to the parties’ national nominating conventions. Among Democrats, Clinton urged Democrats to unite behind her bid to focus on Trump. At a rally in Chicago, Clinton said, “We have the way forward to be able to start talking about not only unifying the Democratic Party but unifying our country.” The violent atmosphere at some Trump events has deepened concern over his candidacy in some Republican circles. Rubio and Kasich have suggested they might not be able to support Trump if he’s the nominee, an extraordinary stance for intraparty rivals.

“I think the candidates need to take responsibility for the environment at their events,” House Speaker Paul Ryan, a leading Republican, said during an interview Monday. “There is never an excuse for condoning violence, or even a culture that presupposes it.”

Trump has denied playing any role in encouraging violence against protesters.

Trump went into Tuesday’s contests with 460 delegates to 370 for Cruz, 163 for Rubio and 63 for Kasich. It takes 1,237 delegates to win the Republican nomination.

Clinton headed into Tuesday’s primary with 768 pledged delegates compared to 554 for Sanders, according to a count by The Associated Press. Including superdelegates, elected officials and party insiders who were free to choose any candidate, Clinton had 1,235 total delegates, while Sanders had 580.