There are renewed calls for a dedicated transport police service following the latest attack on a Dublin Bus driver.

SIPTU says the driver intervened as a group of young people attacked a man lying on the ground at a bus stop on Bachelor's Walk last Thursday afternoon.

The trade union says the group then turned on the driver, injuring his face and body and leaving him very shaken by the incident.

Recent incidents of anti-social behaviour on many public transport including the Sligo to Dublin train service has led to calls for a dedicated transport police force.  

SIPTU representative, Stephen Millane says there are security guards on some public transport services, but they don't have enough powers: