Gunshots were heard near a police transportation vehicle by the site of the Republican National Convention on Tuesday, police sources said. No injuries were reported.
An official at the law enforcement command center overseeing security for the event had no immediate comment.
It was not the first report of gunfire in Cleveland, which is hosting the event where Republicans are expected to name New York real estate developer Donald Trump as their candidate to face likely Democratic opponent and former Secretary of State Hillary Clinton in the Nov. 8 election.
"In a dense urban area you get reports of things like that happening," Cleveland Police Chief Calvin Williams told reporters at a briefing Tuesday morning before the most recent report of gunshots.
(Reporting by Scott Malone and Kim Palmer)