Ugandans began voting in a tense election Thursday under heavy security and an internet blackout.
The internet went down Wednesday night, eve of the vote, with some parts of the country reporting complete disruptions or significant slowdowns.
On Tuesday, Museveni announced the suspension of social media networks and messaging services like Instagram, Twitter and WhatsApp in response to Facebook closing accounts linked to government officials the tech giant said were spreading misinformation.
Yoweri Museveni is seeking his sixth elected term in office after 35 years in power.
The 76-year-old faces 10 challengers, most notably Bobi Wine, 38 whose popularity among a youthful population has rattled the former rebel leader.
President Museveni is one of the longest-serving presidents in Africa. He and his National Resistance Movement came to power in 1986 at the end of a five-year war, and have led Uganda ever since.
The United States, European Union, United Nations and global rights and democracy groups have raised concerns about the integrity and transparency of the election.