Uganda's President Yoweri Museveni has taken a strong lead in provisional results from Thursday's presidential election, the electoral agency says. The results announced on Friday morning put Museveni in the lead with 76% of the votes, based on results from 45% of the country's polling stations. He is followed by opposition leader Bobi Wine with about 20%. Ugandans voted in a tense national election on Thursday after an often violent campaign, with President Museveni, 81, seeking a seventh term in office. Wine, a pop star-turned-politician, has alleged massive fraud during the election, which was held under an internet blackout. He did not provide documentary proof and the authorities have not responded to his allegations. Late on Thursday, Wine's National Unity Platform (NUP) party said that the military and police had surrounded his house in the capital, Kampala, effectively placing him and his wife under house arrest. Voting was delayed by up to four hours in many polling stations as ballot boxes were slow to arrive and biometric machines, used to verify voters' identity, did not work properly. Some have linked the problems to the network outage.