A worker was hurt when 50 to 60 employees tried to seal off the cargo bay area of Dublin Airport this morning.
It is understood the demonstrators were British Midland workers who have been in dispute with their management over a transfer deal to new parent company Gatwick Haulage International for the past three weeks.
More than 150 Irish British Midland baggage-handlers and some cabin crew are due for transfer.
A Garda spokeswoman said the protesters were marching and heckling at the cargo bay area of the airport and the Garda was called to disperse the group at about 5.30.
No arrests were made.
It is believed one of the protesters fell and was slightly injured.
Gardaí said the protesters have moved on towards the main road and access to the airport was unaffected.