Conor McGregor's Dublin-based pub was petrol bombed overnight while the UFC superstar was reportedly inside.
The Black Forge Inn was targetted by criminals, with local police launching an urgent investigation into the disturbing attack.
Garda are looking into the incident after two petrol bombs were thrown at the pub.
They are also probing claims pipes bombs were left at the premises and appealing for witnesses as well as dashcam footage.
Two men were seen on scooters near the venue before the alleged attempted bombing, according to sources via the Dublin Live.
The same source also states McGregor had been holding a taste testing menu at the time of the attack.
Despite the attack, there was no damage to the pub, which was closed.
A spokesperson for An Garda Siochana said: "Gardai are investigating an incident of attempted criminal damage at a licenced premises on the Drimnagh Road, Crumlin last night, Wednesday 12th January 2022.
"No damage was done to the premises. Gardai are appealing for witnesses in relation to this incident is asked to contact Gardai."
They added: "Gardai are particularly keen for anyone with camera footage from the area overnight to make this available to them.
"Anyone with any information is asked to contact Crumlin Garda station on 01 666 2000, the Garda Confidential Line on 1800 666 111 or any Garda station."
The 'Notorious' purchased the pub on Drimnagh Road in Crumlin for £2 million in 2019.
The 33-year-old, meanwhile, is on the mend as he recovers from his broken leg suffered in his defeat to Dustin Poirier last summer.
Featured Image Credit: Black Forge Inn/PA/Conor McGregorTopics: Conor McGregor, UFC