KAMPALA (Reuters) - Ugandan opposition leader Bobi Wine s party said on Sunday that it was preparing to challenge President Yoweri Museveni s election win and condemned what it called the house arrest of Wine, as news emerged of two people killed in protests over the result. Protests broke out on Saturday after results from Thursday s election were announced in two areas, Luwero district north of Kampala and Masaka to the southwest, and security forces killed two people and arrested 23 in total, NTV Uganda reported on Sunday, citing local police. No other details were immediately available about the protests. A nationwide internet blackout since the day before the vote has slowed the flow of information about the process. We have evidence of ballot stuffing and other forms of election malpractice and after putting it together we are going to take all measures that the law permits to challenge this fraud, Maathias Mpuuga of Wine s National Unity Party (NUP) told a news conference. On Sa