At least 84 people have been killed - several of them children - after a lorry driver ploughed into crowds celebrating France's national Bastille Day in Nice.
French President Francois Hollande has described the attack as a "terrorist crime".
Northern Ireland tourists in the popular holiday destination in the south of France have described the chaos and confusion as the attack unfolded.
The Irish foreign ministry say there is no longer concern over a man, thought to have been caught up in the Nice attack which killed 84 people.
They had previously said they were 'very concerned' for his welfare.
Officials say the "vast majority" of Irish citizens in Nice had been accounted for and were safe and well.
They continue to try and make contact with a small number of individuals, but say there is no reason to believe they were caught up in the attack.
Belfast's Lord Mayor and deputy Lord Mayor have opened a book of condolence for those killed in last week's lorry attack in Nice, France.
The Irish Department of Foreign Affairs is "urgently following up" on concerns for the safety of Irish citizens in Nice.
UTV journalist and producer Ben Terry, who was in Nice at the time of the attacks, has described a scene of “mass panic”.