The Ugandan police announced on Monday that they had arrested an American citizen “for his alleged involvement in anti-government subversive activities”.
The US national, Guy Smith, was arrested on Sunday at Fort Portal in the country’s western region, the police said in a post on social media.
It said Mr Smith was being detained as inquiries continue.
“Any new information will be communicated accordingly,” a statement said.
The Reuters news agency quoted a US State Department official as saying the government was aware of the arrest.
“We have seen reports of a detained US citizen in Uganda. Whenever a US citizen is detained overseas, we stand ready to provide all appropriate consular services,” the US official was quoted as saying.