Six people have been arrested after Irish police were attacked with missiles and fireworks, and a police vehicle set on fire, during protests outside a Dublin hotel used to house asylum seekers.

Protests have been held for two consecutive nights outside the hotel, after an alleged sexual assault in the vicinity in the early hours of Monday morning.

Irish Premier Micheal Martin condemned the scenes outside the Citywest Hotel, saying there could be "no justification" for attacks on police.

Garda Commissioner Justin Kelly, who visited the scene in the aftermath of the violence, said: "This was obviously not a peaceful protest. The actions this evening can only be described as thuggery. This was a mob intent on violence against Gardai.

The Irish police service said officers sustained attacks including physical violence, bricks thrown and fireworks.

There were also attempts to charge the police line with horse-drawn carts and he police helicopter overhead was targeted with lasers.

Public order units were deployed in full protective equipment and utilised pepper spray to "repel sustained physical attacks".

A senior investigating officer has been appointed to probe the incident.

Ireland's Justice Minister Jim O'Callaghan has said those involved in the violence will be brought to justice.

He added: "While I am not in a position to comment any further on this criminal investigation, I have been advised that there is no ongoing threat to public safety in the area.

"Unfortunately, the weaponising of a crime by people who wish to sow dissent in our society is not unexpected.

He added: "Peaceful protest is a cornerstone of our democracy. Violence is not.

"There is no excuse for the scenes we have witnessed tonight."