NICOLA Sturgeon has joined an outpouring of tributes to a 29-year-old journalist who was shot dead during unrest in Derry.

Lyra McKee, who was set to become a published author later this year, was hit when a gunman opened fire on police in the Creggan area of the city on Thursday night.

Police have opened a murder inquiry and said dissident republican group the New IRA was probably responsible for the attack.

READ MORE: New IRA prime suspects after journalist shot dead in Derry

McKee worked as an editor for California-based news site Mediagazer, a trade publication covering the media industry.

In 2016, Forbes Magazine named her one of their 30 under 30 in media. She had been working on a new book which had been due to be published in 2020.

A letter McKee wrote to her 14-year-old self was shared widely on social media. It was read by Scotland’s First Minister, who shared it with Twitter users.

“If you read nothing else today, read this letter Lyra McKee wrote to her 14 year old self. It is heartbreaking but life affirming...and leaves me wishing I’d had the chance to meet this brave young woman. RIP Lyra,” Sturgeon said.

Michelle Stanistreet, National Union of Journalists (NUJ) general secretary, said McKee was one of the most promising journalists in Northern Ireland.

She said: "A young, vibrant life has been destroyed in a senseless act of violence."

She added: "A bright light has been quenched and that plunges all of us in to darkness."

Scottish investigative journalism co-operative, The Ferret, for which McKee had written, expressed their “deepest sympathies”, adding that the 29-year-old, who had won acclaim for her reporting on feminist and LGBT+ issues, was a “brilliant journalist”.

Scottish Brexit Secretary Michael Russell tweeted: “Terrible to wake up to news about any death. Terrible to hear about @LyraMcKee. Terrible that guns are back on the streets of #Derry.”

Justice Minister Humza Yousaf added: “Awful news – Lyra was incredibly talented. At a human level a terrible tragedy and thoughts are with Lyra's family, friends and colleagues.”

The SNP’s Westminster leader, Ian Blackford, condemned the attack and warned Ireland must not return to the “terrors of the past”.

Matthew Hughes said he had been left "devastated" by the death of one of his closest friends.

"I just received the heartbreaking news that my friend @LyraMcKee was murdered tonight in a terrorist incident in Derry," he tweeted.

"She was one of my closest friends. She was my mentor. She was a groomswoman at my wedding. I can't imagine life without her, and yet now I must."

Ann Travers, whose sister Mary was murdered by the IRA in 1984, said McKee was a "kind, gentle, witty and stubborn soul".

"I have just heard, that my lovely friend Lyra was murdered tonight in Derry. I just can't believe, that this witty, clever human being has been taken... Feel sick."

Fellow journalist Peter McGuire said McKee was a "gifted writer, a kind person and SO generous with her time and knowledge".

"So young – horrific & heartbreaking news from Derry tonight," he tweeted.