Gardaí investigating a significant disturbance in central Dublin at the weekend are trying to establish if there are any links to violence that was feared at the Longitude festival in the city.

The three-day concert in Marlay Park, Rathfarnham, passed off without any serious incidents, despite fears of violence voiced in advance by the US embassy in Dublin.

Gardaí have begun an investigation into an attack later by a group of men and youths outside the Lost Lane nightclub off Grafton Street just after 1am on Sunday.

Members of the group tried to storm the nightclub’s door, but they scattered after gardaí arrived. An assortment of weapons was found nearby, including knives, hatchets and petrol bombs.

In reply to queries about the incident yesterday, the Garda said: “Investigating gardaí at Pearse Street Garda station have not identified any definitive motive for this incident. Investigations are ongoing.”

Music promoter Denis Desmond insisted yesterday there was “no connection” between the Lost Lane violence and Longitude, which is promoted by his company, MCD. “I’ve no idea what happened. I’m not the police, so I don’t know. Deal with facts.”

Ahead of Longitude, gardaí learned of the possibility that two groups were planning to fight at the concert, but this intelligence did not significantly change their policing plan.

The information suggesting two factions might clash was not regarded as proof that there was a significant and immediate threat of violence at the event.

However, such threats are taken seriously since the 2012 Swedish House Mafia concert in Phoenix Park, at which several people were. That increased concerns around any intelligence suggesting violence at large open air concerts requiring a significant policing and security operation.

Having learned of the intelligence, the US embassy warned its citizens in Dublin that “a potential for violence” existed at Longitude, though gardaí were concerned that the embassy warning overplayed the risks.