MANILA — President Rodrigo Duterte of the Philippines suffered bruises after falling off a motorcycle, his aides said on Thursday, amid mounting public concern about his health.

He appeared later that day at a business forum in Manila, seemingly unhurt, and dismissed the accident as a minor incident.

His spokesman, Salvador Panelo, had said earlier that Mr. Duterte, 74, stumbled off his bike Wednesday night at the compound of his security staff.

“While it is true that the president roamed around with his motorcycle, the incident occurred when he had already parked his motorcycle” at the security compound, Mr. Panelo said.