Tanzania’s President John Magufuli has won re-election with a landslide victory in a poll that the opposition has described as fraudulent.

Mr Magufuli’s main rival, Tundu Lissu, has said his party’s agents were prevented from entering polling stations during Wednesday’s election.

The National Electoral Commission (NEC) has dismissed the claims of fraud.

In its final results, the NEC said the president took 84% of the vote, while Mr Lissu received 13%.

An observer mission from the East African Community said on Friday that the election was “conducted in a regular manner”.

On Thursday, Mr Lissu, who was the candidate for Chadema, said he would not accept the results saying the vote was “was not an election by both Tanzanian and international laws. It was just a gang of people who have just decided to misuse state machinery to cling to power.”

He alleged that ballot boxes were tampered with while his party representatives were not present.

The US embassy in Dar es Salaam said that “irregularities and the overwhelming margins of victory raise serious doubts about the credibility of the results… as well as concerns about the government of Tanzania’s commitment to democratic values”.

The head of the National Electoral Commission, Semistocles Kaijage, said allegations of fake ballot papers were unsubstantiated.

As well as taking part in the Tanzanian elections, voters on the semi-autonomous archipelago of Zanzibar were also electing their own president, and the CCM candidate Hussein Mwinyi has been declared the winner with 76% of the votes.

His main rival, Maalim Seif Sharif of ACT-Wazalendo, got 19% – his biggest defeat in any presidential election he has taken part in.

On Thursday, Mr Seif Sharif was arrested shortly after saying that the polls had been rigged and calling for mass protests. He was later released on bail.