President Nayib Bukele of El Salvador, credited with driving down gang violence in the Central American nation, says he has been re-elected.

The 42-year-old took to social media to say he had won 85% of the vote.

Preliminary results later showed him winning 83% with 31% of votes counted.

His popularity has soared following a crackdown on crime that has transformed El Salvador from one of the most violent countries in the world to one of the safest in Latin America.

Mr Bukele, a former mayor of the capital, San Salvador, has described himself as "the world's coolest dictator".

He declared himself the winner before the official results were announced, telling his cheering supporters that he had achieved "the biggest difference between first place and second place in history".

He also praised his party's performance in the legislative election, which he credited with winning at least 58 out of the 60 seats in the National Assembly: "This will be the first time where one sole party rules a country in a completely democratic system. We pulverised all of the opposition [in the polls]."

The preliminary results, released later by the electoral authorities as his supporters let off celebratory fireworks, appeared to support his claim of having won a second term by a landslide.

With 31.5% of votes counted, Mr Bukele's Nuevas Ideas (New Ideas) party had close to 1.3 million votes, while the second-placed FMLN party had just over 110,000 and the third-placed Arena party was shy of 100,000 votes, the Supreme Electoral Tribunal announced.

On X, formerly known as Twitter, his party uploaded footage of the 42-year-old and his wife stepping on to the balcony of the National Palace to wave to thousands of jubilant Salvadoreans, waving the party's light-blue flags and chanting his name.

Ahead of Sunday's vote, he had warned voters that his achievements could be reversed if he was not re-elected.

Among those celebrating the election outcome was 55-year-old Guadalupe Guillen, who told Reuters news agency that she was "thanking him [Nayib Bukele], thanking God, for getting us out of this gang problem. We don't want to go back to that horrible past."

The shopkeeper also told Reuters that thanks to the improving security situation, she no longer had to pay $300 (£240) in extortion to the gangs every fortnight.

Despite his popularity, Mr Bukele remains a controversial figure. Human rights groups say that thousands have been arbitrarily arrested during his anti-gang drive.

An estimated 75,000 people have been arrested under emergency measure that have been repeatedly extended.

In a report in December, Amnesty International criticised the "gradual replacement of gang violence with state violence".

Mr Bukele's re-election bid itself has also been criticised. He is banned under the constitution from standing for a consecutive second term.

But in 2021 the constitutional court - which is dominated by his supporters - allowed a president to stand again, provided he or she stands aside in the period before a second term.

Mr Bukele nominally stepped down as president several weeks ago to fulfil that requirement. He is to be sworn in in June.