An 18-year-old man remains in custody following a fatal knife attack in Dundalk on Wednesday.
Japanese national Yosuke Sasaki, 24, died after he was stabbed in the back as he walked along Avenue Road in the County Louth town.
An Egyptian teenager was arrested on suspicion of murder.
The Gardaí (Irish police) say they can find “no established link” to indicate the attack is “terrorist related”.
Two other victims were taken to hospital but their conditions are not believed to be life-threatening.
The Gardaí said they are liaising with international partners to “assess any relevant intelligence”, and the investigation is on-going.
The threat level from international terrorism in the Republic of Ireland remains unchanged at “moderate”.
Speaking on Wednesday Ch Supt Christy Mangan said the suspect had been in contact with immigration police on New Year’s Day in relation to a possible application for residency in the Republic of Ireland, and there was no indication of any involvement in criminality.
He said police were trying to establish how the murder suspect “arrived in this jurisdiction” and would be speaking to Egyptian authorities regarding his movements.