WASHINGTON (AP) — Senior U.S. national security officials say they are worried about the potential for violence at the Republican National Convention to be held in Cleveland next week.

During congressional testimony Thursday, Homeland Security Secretary Jeh (jay) Johnson said he’s concerned that demonstrations outside the convention hall may get out of hand.

Johnson says he will be inspecting the security around the convention hall during a visit Friday. He says he says similar concerns about the Democratic convention to be held in Philadelphia. He’ll be visiting that site next week.

Johnson tells the House Homeland Security Committee there will be 4,000 U.S. government security personnel in Cleveland.

FBI Director James Comey says anytime there is a large, national event there is concern that radical people and groups may be drawn to it.