The largest independent election observer mission in Zimbabwe says the official results from the presidential poll are broadly consistent with its own findings.

The Zimbabwe Election Support Network (Zesn) studied a sample from 750 polling stations and whilst agreeing that the incumbent Emmerson Mnangagwa won the most votes, it says it cannot definitely confirm whether or not there should have been a run-off.

The electoral commission said Mr Mnangagwa had secured 50.8%, narrowly avoiding the need for a second round.

The opposition leader, Nelson Chamisa, says he will produce evidence to back up his claim that the election result was rigged.

The Zimbabwe Electoral Commission (Zec), which announced the results, said there was "no skulduggery" involved in the vote tally.

But EU observers said they had found an "un-level playing field and lack of trust" in the election process.