Tributes have been paid to 29-year-old journalist Lyra McKee who was shot dead during riots in Derry last night.
President Michael D Higgins described Ms McKee as "a woman of talent and commitment"
"The people of Ireland will have heard with both shock, outrage and great sadness of the killing of the young journalist Lyra McKee in Derry last evening - a woman of talent and commitment, who was shot exercising her profession," he said in a statement.
"Sabina and I send our deepest sympathies to her family and friends and to all those who knew her and worked with her."
Politicians on both sides of the border condemned the violence in Derry during which Ms McKee was hit when a gunman opened fire on police in the Creggan area of the city.
Taoiseach Leo Varadkar he was "full of sadness" after last night's attack.
“The Government condemns in the strongest possible terms the fatal shooting of journalist and writer Lyra McKee in Derry," he said.
“I would like to express my sincere condolences to Lyra’s family, her partner Sara and her friends. Our solidarity also goes out to the people of Derry and to the entire journalism community.”
Tánaiste Simon Coveney said he was "sick to my stomach" at the death of the "an inspiring thinker and journalist".
Sick to my stomach at death of Lyra McKee in Derry. She was an inspiring thinker and journalist. Last night she was killed by a thug terrorizing people in Derry. Anyone with information should contact #PSNI .— Simon Coveney (@simoncoveney) April 19, 2019
He said there " is no justification for this tragic loss of life" and called on people perpetrating the violence to stop.
"The news from Derry is shocking and tragic. Our thoughts are with the family and friends of Lyra McKee today. I call on anyone with information to come forward to the PSNI," he said.
"As we mark the 21st anniversary of the Good Friday Agreement, we are reminded that the vast majority of people of this island voted overwhelmingly for peace and reconciliation and an end to violence. There can be no going back to those awful days."
Fianna Fáil Leader Micheál Martin said the murder was "appalling and deeply shocking" and that the "shooting and associated riots are an attack on democracy".
"I utterly condemn the attack which initial reports suggest is the work of the so called New IRA. Those responsible must be brought to justice and I encourage anyone with information to bring it to the attention of the authorities," he said.
"The PSNI have worked hard to engage with communities across the political divide over the last decade.
Sinn Féin leader Mary Lou McDonald said the death of Ms McKee was "beautiful life brutally stolen".
She wrote on Twitter: "Heart sore for Lyra and her grieving family. Today I travel to Derry to stand with its proud people, to face down hate and destruction. We shall overcome."
A beautiful life brutally stolen. Heart sore for Lyra and her grieving family. Today I travel to Derry to stand with its proud people, to face down hate and destruction. We shall overcome. https://t.co/wEa6rAy21h— Mary Lou McDonald (@MaryLouMcDonald) April 19, 2019
The party's deputy leader Michelle O’Neill said the killing was a “senseless loss of life", "a human tragedy for her family, but it is also an attack on all the people of this community, an attack on our peace process and an attack on the Good Friday Agreement".
DUP leader Arlene Foster tweeted: “Heartbreaking news. A senseless act. A family has been torn apart.
“Those who brought guns onto our streets in the 70s, 80s & 90s were wrong. It is equally wrong in 2019."
Northern Ireland Secretary Karen Bradley said: "I am deeply shocked and saddened to hear of the death of a woman in Derry last night.
"Those responsible for last night's violence have nothing to offer anyone in Northern Ireland.
United States House of Representatives speaker Nancy Pelosi also paid tribute to journalist Ms McKee during a visit to Stormont.
A minute's silence was observed during an event she attended in the Long Gallery in respect of Ms McKee during a speech by Northern Ireland Assembly speaker Robin Newton.
During her speech, Ms Pelosi said: "Sadly, Mr Speaker, we join you on the sadness of the tragedy that happened last night, we extend our condolences to the family and your moment of silence at this time, on Good Friday is especially poignant.
Meanwhile, British Prime Minister Theresa May said: "The death of Lyra McKee in last night's suspected terrorist incident in Londonderry is shocking and truly senseless.
"My deepest condolences go to her family, friends and colleagues.
"She was a journalist who died doing her job with great courage."
A GoFundMe campaign has been set up this morning in memory of Ms McKee, with all the money raised going to her family for funeral expenses and to decide on her legacy.
You can donate here.
A journalist has been killed covering riots in Derry. Her name was Lyra McKee. She was 29. She recently signed a two-book deal with Faber, who called her a "rising star of investigative journalism". This is her last tweet, sent from the scene of the unrest. pic.twitter.com/0gk1Fa7Du0— Naomi O'Leary (@NaomiOhReally) April 19, 2019
Additional reporting PA