Malende, who was welcomed by supporters at Entebbe International Airport, held a brief procession en route to Kampala when police intercepted and arrested her.
The circumstances surrounding the arrest remain unclear, but eyewitnesses say the procession was peaceful until security forces intervened.
Malende has been away receiving medical treatment, and her return had been anticipated by supporters and political allies.
Efforts to reach the police for a comment on the arrest were still ongoing by the time of publication.
This is a developing story, Nile post will share more details as they unfold