The Tánaiste has described this morning's fatal stabbing in Dublin city centre as "alarming, shocking and deeply concerning".
It is understood the incident occurred following a row between two groups of people out socialising.
Speaking in Munich, Simon Harris said the incident will have caused concern for many people across the capital and beyond.
The Tánaiste said Minister for Justice Jim O'Callaghan is being kept updated on a regular basis by the Garda Commissioner in relation to the fatal stabbing.
He said the minister is "working tirelessly" with Government colleagues to increase the number of gardaí on the streets of Dublin and right across the country.
"I am very conscious there is an active ongoing murder investigation that's now been opened in relation to this issue, we have seen the loss of life of one person and another person who is seriously injured in hospital, we need to obviously to let that murder investigation proceed."
Minister O'Callaghan said: "An Garda Síochána are keeping me updated on the shocking incident which occurred early this morning on Dawson Street.
"Dubliners deserve to feel safe in our city. That's a priority."
Sinn Féin's justice spokesperson has described the incident as "deeply disturbing" and said that it caused great shock.
Matt Carthy said that there is a "serious problem" in relation to public safety in Dublin city centre, and said that there are not enough gardaí on the streets.
He called on Minister O'Callaghan to urgently "bring forward a plan to make Dublin, our capital city, safe for all those who live, work, do business there as well as for visitors to the city".
Dublin MEP Aodhán Ó Ríordáin has called for "real action" to tackle crime, dereliction and anti-social behaviour in Dublin city centre.
In a statement, he said that the death of the man was heartbreaking and that more gardaí need to be visible in Dublin.
Dublin businesses call for more gardaí
Sean Phillips of Kehoes Pub on South Anne Street said that there has to be "more guards on the beat in around the city centre".
"There's ten or 12 businesses closed today and Saturday is one of our busiest days," he said.
"You just see the blood on the street. That's horrendous of a Saturday morning."
Ash Thulsee, the manager of Gotham Cafe was also taken aback.
"You're kind of startled," he said, "You wouldn't expect that in, you know this kind of, you know, city centre area.
"Obviously being a Saturday sort of peak peak trading times. You know it's definitely going to have a major effect on us."
Customers too were affected. Will Leigh Bramwell had travelled from London to Dublin for a specific task.
"I'm a little bit sad," he said.
"I was here to pick up a suit for my wedding, which is in May.
"So we had an appointment at Magees, just down the road there...but it doesn't look like we can get in."
