Uganda's Yoweri Museveni has won a sixth term in office, extending his 35-year rule after an election which took place under heavy security and an internet blackout, and which his main rival said was marred by fraud and violence.

The election commission said Museveni won in a landslide, with 58.64% of the vote, while opposition Wine received 34.83% of the vote.

Museveni's main challenger, musician-turned-politician Bobi Wine had accused him of fabricating the results and called the poll "the most fraudulent election in the history of Uganda".

On Saturday, the electoral commission declared Mr Museveni the victor, with final counts showing the president won 59pc of votes to Mr Wine's 35pc.

Mr Museveni (76), in power since 1986 and one of Africa's longest-serving leaders, said after he was declared victor that the election may turn out to be the "most cheating-free" in Uganda's history.

Mr Museveni, in a wide-ranging speech on state television after the announcement, thanked his supporters and said that now, "the only thing to avoid is violence".

The internet has been down for four days, and government spokesman Ofwono Opondo said the measure was taken due to "abuse, misuse, disinformation, fake news with the overall objective of undermining the integrity of the electoral process including the results... and possibly to cause destabilisation".

Wine and other opposition candidates have been arrested on several occasions, and during protests that followed one arrest in November, more than 50 people were killed.

Army deputy spokesman Deo Akiiki told Reuters that security officers at Wine's house were assessing threats he could face: "So they might be preventing him in the interest of his own safety". The UK is concerned by the national internet shutdown, which clearly limited the transparency of the elections, and constrained the freedoms that Ugandans are entitled to.

The government banned all social media and messaging apps on Tuesday.

After the results were announced, many neighbourhoods in normally bustling Kampala were unusually quiet as nightfall approached.

The United States, a major aid donor to Uganda, cancelled a diplomatic observer mission after too many of its staff were denied permission to monitor the election, and aside from an African Union mission there was no major worldwide group watching over the vote.

Bosco said Museveni should just bar elections if he feels he still wants to be president, because the current practice was frustrating for Ugandans.

"I'm alive", Wine said.

He reiterated his calls for the United States and European Union to hold Museveni and his government "accountable to free and fair elections", accusing the leader of forcing the country to "carry out elections in the dark" with his internet blackout.

The EU's foreign affairs chief Josep Borrell said the commission rejected its offer of monitors, despite having observed three elections between 2006 and 2016.

"We did not receive any orders from above during this election", commission chief Simon Byabakama told reporters Saturday, adding his team was "neither intimidated nor threatened".

Opposition leaders rejected the election results, saying they would not live like serfs and that the results were fabricated. "I am very, very happy".

Mr Owoyesigyire further said two people tried to jump over Wine's fence but that they stepped in and arrested one while the other escaped.

Legislator Francis Zaake, a Wine supporter who in the past has been arrested and allegedly tortured by security forces, was given access, only to be stopped at the roadblock.

Yoweri Museveni (left) and Bobi Wine.