Police in Derry are becoming increasingly concerned for the welfare 71 year old John Concannon.
Mr Concannon was last seen yesterday evening in the city centre of Derry.
He is described as being about 5'6" tall, of medium build and with grey hair. He was wearing a black and grey beanie hat, a black coat, checked shirt and navy trousers.
Mr Concannon has medical conditions which cause extra concern for his wellbeing.
Mr Concannon, or anyone who knows of his whereabouts, is asked to contact Strand Road Police Station on the non-emergency number 101.