Uganda's main opposition party said its leader Bobi Wine had been detained on Thursday at the airport as he returned from a trip abroad, but police said they had accompanied him to his residence.

In recent years Robert Kyagulanyi, popularly known as Bobi Wine, has emerged as the strongest challenger to President Yoweri Museveni, 79, who has been in power in the east African country since 1986. Wine finished runner-up to Museveni in a 2021 election that he said was marred by fraud.

Museveni's government has faced criticism from opponents and human rights activists for stifling the opposition, a charge Museveni denies.

A video posted by Wine's National Unity Platform (NUP) on messaging platform X showed the leader being led away after disembarking from a plane in Entebbe. One of his associates was heard on the video saying "Where are you taking him?"

"The cowardly regime has arrested our President upon arrival at Entebbe Airport. We set out to receive him today, but the panicky regime security could not even allow him into immigration," Mathias Mpuuga, the NUP leader in parliament, posted on messaging platform X.

Police spokesperson Patrick Onyango said security agencies accompanied him to his residence in Magere, Kasangati.

The NUP posted on messaging platform X that police officers had surrounded their offices.

Police said in a statement on Wednesday anyone on the streets to welcome Wine would be arrested after the NUP called for a million-man march.

"Such a procession has the potential to disrupt the normal flow of traffic, the movement of individuals, and the operations of businesses ...through acts of theft or other criminal activities," the police said in a statement.