A journalist was shot dead in the border city of Londonderry in Britain's Northern Ireland during rioting that police are now treating as a "terrorist incident," local media reported on Friday.

Lyra McKee, 29, was named as the victim after shots were fired, petrol bombs thrown and cars torched during rioting in Creggan area of the city on border with the Republic of Ireland.

The assistant chief constable, Mark Hamilton, from the Police Service of Northern Ireland, said a murder inquiry had been launched after the woman's death late Thursday evening.

"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 IRA are most likely to be the ones behind this and that forms our primary line of inquiry," Hamilton said.

The Irish border area was a flashpoint during the decades of conflict that cost over 3,600 lives after the 1960s. The Irish Republican Army (IRA) waged a campaign for the reunification of the island, leading to 30 years of what is known as "the Troubles." It laid down its guns in favor of pursuing a political solution in 1998.

Thursday's violence broke out after police were carrying out a search operation looking for firearms that may have been used over the Easter weekend, which marks the anniversary of the 1916 Easter Rising, a time when dissidents are traditionally active.

Northern Ireland Secretary Karen Bradley said the "intolerable actions" of those behind Ms McKee's murder were "rejected by the overwhelming majority of people who want to build a peaceful and more prosperous future for everyone in Northern Ireland."