Karua had just arrived at the Entebbe airport to join a team defending her Ugandan lawyer colleague Erias Lukwago, with whom they have been representing detained opposition leader Kizza Besigye, who is on trial for treason.

Lukwago was himself charged with a treason-related offence last week, and his bail hearing had been due on Monday.

Ugandan authorities did not give a reason for blocking Karua, although Kenya's Law Society President Charles Kanjama, who had travelled with her, was allowed in.

Kanjama said it was "of particular concern" that Karua was blocked, despite her travelling "for the same matter and in the same professional capacity" as himself.

"It is difficult to understand why one member of a defence team should be admitted while another is turned away," he said in a post on X, while calling on Ugandan authorities to explain their actions.

According to BBC, Uganda's immigration authorities have not responded to a request for comment.

Karua’s office described the situation as urgent and said efforts were ongoing to obtain information from Ugandan authorities regarding her status and expected return to Nairobi.

Lukwago appeared in court last Wednesday looking weak days after he had been arrested at his home.