Thousands partied along Havana's Malecon seafront into the early hours of Saturday, celebrating retired Cuban leader Fidel Castro turning 90 to the tune of Latin beats as an electric storm in the distance lit up the night sky.

On the strike of midnight, a live band played ‘Happy Birthday’ in honour of the iconic leftist revolutionary on the ‘Anti-imperialist Tribune’, a plaza located outside the newly-opened US embassy, while fireworks exploded on the other side of the bay.

Colourful floats carrying dancers and salsa bands stretched for kilometers down the Malecon, as Havana's annual carnival was combined this year with Fidel's birthday concert.

‘This is the best gift we can give him, this party,’ said dancer Leydis Campos, 25, decked in a skimpy limegreen outfit, her eyelids caked in glitter.

‘To 90 years past, and to 90 more!’

Cuba has gone into overdrive this month honouring ‘El Comandante’ who led its 1959 revolution and built a Communist-run state on the doorstep of the United States, surviving what it claims were hundreds of assassination attempts along the way.

Tributes have ranged from the conventional such as photo exhibits about his life, to the outlandish, with one cigar maker rolling the longest smoke in the world, measuring 90 meters, in Fidel's honour.

While many Cubans criticize Castro for having restricted personal freedoms and imposed a Soviet-style command economy, others revere him for having freed Cuba from US domination and provided universal access to healthcare and education.

‘Fidel is the best thing that happened to our country,’ said Aldo Zamora, 40, selling candy-coloured balloon animals.

Fidel handed over the reins of power in 2008 to his younger brother Raul due to an intestinal ailment that nearly killed him, although he retained the title ‘Historic Leader’.

Since then, he has ventured into public rarely, looking increasingly frail and sporting comfortable tracksuits and trainers instead of his trademark olive green military fatigues.

He is not scheduled to appear in public for his festivities although he could meet with Cuba's ally Venezuelan President Nicolas Maduro who arrived in Havana early on Saturday.

Some Cubans say they miss the charismatic leader who accompanied them for decades, holding forth on topics from nuclear energy to farming in famously long speeches, lending the revolution moral authority and him a sense of invincibility.

‘His words gave us a sense of confidence,’ said Yadira Escudero, 25.

Yet, even those party-goers said they welcomed the changes that have taken place since a more pragmatic Raul took power, such as market-style reforms, detente with the United States and greater personal freedoms such as the right to travel.