Police investigating the murder of a heavily-pregnant teenager say they believe the crime was "locally based" and that the answers lie within the community.

A post-mortem examination has revealed Nikitta Grender had been stabbed before the fire in her Newport flat took hold.

The murder investigation has revealed Ms Grender was eight months pregnant and due to give birth to a baby girl in two weeks.

Officers and firefighters were called to the scene on Saturday after neighbours reported the blaze at her flat in Broadmead Park in Liswerry, Newport, south Wales, at 7.50am.

Emergency crews entered the smoke-filled property and found the 19-year-old's body inside the bedroom of the first-floor flat. Her pet dog, a pug cross, also died in the fire.

Officers are still searching for the murder weapon, believed to be a knife.

Detective Superintendent Geoff Ronayne of Gwent Police said: "This is an horrific crime where two innocent lives have been lost.

"We know Nikitta was out with friends Friday evening and visited McDonald's in the Spytty area during the evening, and we are establishing the exact time she was dropped back to her address, but we would urge anyone who was in the vicinity of Nikitta's address in 51 Broadmead Park, was with her or who saw her at any stage from 7pm on Friday February 4 onwards to get in touch.

"Someone must know who did this and we are urging members of the community to come forward and help us with this inquiry."

He said it was one of the "worst offences" he had seen, adding: "We are working on the basis that this crime is locally based.

"Somebody knows where the knife is and we urge them to come forward.

"Someone will know who is responsible. Please come forward to give us that information that we need."