Voters queued to cast their ballots in Uganda's presidential election on Thursday, following a run-up tainted by widespread violence that some fear could escalate as security forces try to stop supporters of leading opposition challenger Bobi Wine from monitoring polling stations.

In the election, Wine, a popular young singer-turned-opposition lawmaker, and nine other challengers are challenging incumbent President Yoweri Museveni, a 76-year old who has wielded power since 1986.

Internet remains cut off across the east African country. Opposition presidential candidates have also reported that they cannot make or receive calls.

Polls officially closed at 4pm local time (13:00GMT). The electoral commission however allows those found lining up before close of voting to cast their ballots.

Local broadcaster NTV reported that incumbent President Yoweri Museveni voted in his home district in Western Uganda minutes before polls closed.