Ugandan police have arrested at least three people over the killing last month of a senior prosecutor who was involved in the trial of a dozen men accused of belonging to the Somali armed group al-Shabab.

Ugandan police chief Kale Kayihura told reporters on Tuesday that the suspects — who once lived in the Kampala neighborhood where prosecutor Joan Kagezi was shot dead — had changed their physical address three times, leading a surveillance team to suspect they played a role in the killings.

Police on Tuesday searched an apartment on the outskirts of Kampala that the suspects occupied before they were arrested. They were not identified.

Ugandan police suspect Islamic extremists killed Kagezi because of her public role as a senior prosecutor who handled international crimes and terror cases.