The Journal.ie has found that a group of young men are believed to be behind a number of serious incidents involving taxi drivers in West Dublin.
On New Year's Eve, one driver was threatened with a fake gun and robbed in Clonee.
The incident occurred when two teenagers - both male - got into his car in the city centre before pulling a gun out on the driver in the west Dublin area.
The driver was forced to hand over his smartphone and the pair also demanded money but the driver had very little cash on him at the time.
There have been a series of incidents like this in the west of the capital since December and many taxi drivers are refusing to pick up or drop off clients in certain parts of Ongar, Clonee and Tyrellstown.
The National Transport Authority has encouraged drivers not to travel to certain areas if they feel unsafe.
The NTA has also said that drivers shouldn't be alarmed if a customer makes a complaint about being refused service.