Dana White has ignited fury after smoking a cigar and boasting about his 'great day' just hours after the tragic death of one of his UFC fighters.

Allan Nascimento, who spent the last five years with White's UFC promotion, died at the age of 34 on Monday after suffering an 'apparent heart attack' in his sleep.

The Brazilian's shock passing comes just six weeks after his last fight in Las Vegas on June 20, when he suffered a split decision loss to Mitch Raposo at UFC Vegas 119.

Shortly after the news was announced, White shared the UFC's tribute post to Nascimento on his Instagram story Monday night.

Yet two hours later, White left fans seething by following it up with a photo of himself puffing on a cigar with the caption: 'Great day' along with a smiling emoji.

'Dana is so tone deaf its actually insane,' one user wrote on X.

'Gotta be one of Dana White’s worst timed IG story posts ever,' said another.

A third put: 'Posting this s*** back to back might be the dumbest s*** I’ve ever seen in my life man.'

A fourth commented: '‘Great day’ says the totally checked out Dana White on one of the worst days in the promotion’s history.'

While a fifth simply said: 'Read the room, man....'

The UFC announced Nascimento's death on Monday night, writing: 'This morning, Monday, August 3rd, our beloved flyweight fighter, Allan Nascimento, was found unresponsive after suffering an apparent heart attack in his sleep.

'Despite the efforts of the responding medical team, he was pronounced deceased at the scene.

'Our thoughts and deepest condolences are with Allan's family, friends, teammates, and loved ones during this incredibly difficult time.'

The statement was accompanied by a single black-and-white photo of him smiling, while he held up his fist in a UFC glove.

Born in Sao Paulo, Nascimento built an impressive reputation by winning 17 of his first 22 fights.

A flyweight, the 'Puro Osso' - a Portuguese idiom meaning 'skin and bones' - competed in multiple promotions during his career, including RIZIN, Legacy FC and Dana White's Contender Series.

Nascimento then joined the UFC in 2021 and won four of his six fights. He finished his career with a 22-7 professional record.

He managed to secure the Performance of the Night bonuses for impressing fans in submission victories over Carlos Hernandez and Cody Durden.

Former UFC lightweight champion Charles Oliveira, who trained with Nascimento in Sao Paulo, posted an emotional tribute on social media.

He wrote in Portuguese: 'Today I lost a brother that the fight game gave me. Thank you for always being by my side, for sharing the mats and the corner.

'I have nothing but gratitude for having you with me - in training, in the corner, and just hanging out. I love you, man; you're a legend. My brother, I can’t even believe it; you will be deeply missed.'