CLEVELAND, Ohio — Amid a political environment in which a prominent supporter of Donald Trump has threatened to publicize their hotel room numbers, GOP delegates have expressed concerns about their safety when they travel to Cleveland for the Republican National Convention.

In convention-planning briefings during last week's Republican National Committee conference in Florida, some GOP officials said they had received death threats, and asked staffers planning the event what they planned to do to keep them safe.

Why are delegates uneasy?

Donald Trump in March predicted "riots" if he were to be denied the nomination at the Republican National Convention. But one of the biggest sources of heartburn for GOP delegates is Roger Stone, a longtime Trump adviser, who has urged Trump supporters to visit the hotels where delegates will be staying during the convention.

Stone has promised "Days of Rage" protests in Cleveland. He has called on thousands of Trump supporters to travel to Cleveland to try to "Stop the Steal" — i.e., prevent Trump from being blocked at the Republican convention.

"We're going to have protests, demonstrations," Stone said during an April 4 appearance on an Internet radio show. "We will disclose the hotels and the room numbers of those delegates who are directly involved in the steal. If you're from Pennsylvania, we'll tell you who the culprits are. We urge you to visit their hotel and find them."