Banks across the European Union (EU) are being robbed at a rate of one every 90 minutes, according to the European Banking Federation trade body.
The Northern Bank raid of 2004 saw £26.5m stolen in Belfast
Its report also highlighted the growing use of violence in the raids, such as the kidnapping of staff during the 2004 Northern Bank robbery in Belfast.
The organisation also found increased use of explosives or heavy weapons.
During 2004 there were 5,864 bank robberies across the EU, Switzerland, Norway and Iceland, it found.
The European Banking Association said that while this represented a slight increase on 2003's numbers, the use of violence had risen more rapidly.
"While the number of robberies of bank branches has generally seen a small rise, some tendencies are more worrying: the violence of certain modus operandi and the means used by the perpetrators," it said.
It blamed "organised gangs, operating across borders [using] any means available to them, including heavy weapons and explosives".
The association also predicted that this violence would only grow as robbers tried to keep up with increased bank security.
"It is to be feared that criminals will resort to higher levels of violence to arrive at their aims," said the report.
"Indeed, the increasingly higher investment by banks as regards branch security forces criminals to find other means to get at the money."
It added that there were now two main types of bank robbers - the professional who is very well prepared and willing to use extreme violence; and the amateur, who is happy to settle for a smaller amount of cash in more opportunistic raids.