Police say they have launched a murder inquiry into the killing of 29-year-old Lyra McKee in Londonderry.

A female journalist was shot dead during a riot in the Northern Irish city of Londonderry, also known as Derry, late on Thursday in what police called a terrorist act.

Lyra McKee, 29, was standing near police officers when a gunman began shooting at them at around 11pm in the suburb of Creggan, Assistant Chief Constable Mark Hamilton told reporters on Friday.

“She was taken away in a police Land Rover to Altnagelvin Hospital but unfortunately she has died there. We have now launched a murder inquiry here in the city,” he said.

“We believe this to be a terrorist act, we believe it has been carried out by violent dissident republicans. Our assessment at this time is that the new [Irish Republican Army] are most likely to be the ones behind this, and that forms our primary line of inquiry.”

We believe this to be a terrorist act, we believe it has been carried out by violent dissident republicans Mark Hamilton, assistant chief constable

He said police had been carrying out search operations in the area on Thursday when a public order situation developed in which 50 petrol bombs were thrown at police and two cars were hijacked and set on fire.

The New IRA is a small group of republicans who reject the 1998 Good Friday agreement that marked the Irish Republican Army’s embrace of a political solution to the long-running violence known as The Troubles, which claimed more than 3,700 lives.

‘An attack on peace process’

The group is also blamed for a Londonderry car bombing that did not cause any injuries in January.

The latest unrest came just before the Easter weekend, when republican dissidents, who want to reunify Northern Ireland with the Republic of Ireland, traditionally mark the anniversary of the 1916 Easter

Uprising against British rule.

Michelle O’Neill, deputy leader of Irish republican party Sinn Fein, condemned those responsible for the killing in a statement, saying it was an attack on all the community.

“My first thoughts and that of my party are with the family of the woman killed. This is a senseless loss of life,” O’Neill said.

My first thoughts and that of my party are with the family of the woman killed. This is a senseless loss of life Michelle O'Neill, deputy leader of Sinn Fein

“The murder of this young woman is 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,” she added, referring to the peace accord reached between the British and Irish governments in 1998.

McKee was writing a book on the disappearance of young people during three decades of sectarian violence in Northern Ireland. She was described by publisher Faber as a rising star of investigative journalism.

Police said they did not believe she was working at the time of the attack.