Police have advised women to take care after an American artist was stabbed to death in an east London park while she was out jogging.

Margaret Muller, 27, was found dead in Victoria Park, Hackney, on Monday morning.

Detectives believe she may have been out for a regular run when she was killed in a "frenzied and callous attack".

They are studying other recent attacks in the area, including one last week in nearby London Fields, when a woman was assaulted by a man wielding a knife.

Ms Muller's identity was not confirmed until Tuesday, after police traced her from a phone and a set of keys she was carrying.

Margaret Muller specialised in life painting

Ms Muller, who lived alone, had been a student and more recently a teaching assistant at the Slade School of Fine Art, part of University College London (UCL).

Ms Muller was born in Virginia, USA and had come to the UK in 1998. Her parents, said to be "devastated", still live in Virginia.

Her body was found after a cyclist, someone walking a dog and a jogger heard screams at about 0830 GMT on Monday.

Description issued

About 50 officers have been searching the park and surrounding areas for the murder weapon - believed to be a four-inch (10cm) knife.

Police have issued a description of a man they want to speak to, seen in the area at the time of the murder.

We are extremely concerned at the frenzied attack and the fact it was in broad daylight Det Chief Supt John Shatford

He is white, aged between 18 and 20, between 5ft 6in and 5ft 8in tall, with short brown hair and a London accent.

Detective Chief Superintendent John Shatford said police were extremely concerned by the frenzied nature of the attack and the fact that it was in broad daylight.

He said he was "keeping an open mind" on whether the man was a stranger to her.

Local resident Caroline Rogers, who is training for the London marathon and runs in the park most days, has changed her route to a nearby canal.

Tribute from colleagues

"I just think it's terrible. I mean, what must her family and her friends be going through, it's awful, awful. She was just out for a run," she said.

"But having said all that, I think it would be wrong if everybody stopped running. I'm not going to stop running and I won't stop using the park."

It's awful, awful - she was just out for a run Local resident Caroline Rogers

Officers said there was no indication of a sexual assault, although that may have been the attacker's motive.

A post-mortem examination confirmed Ms Muller died from multiple stab wounds, while an inquest is due to be opened and adjourned at Poplar Coroner's Court on Wednesday.

In a statement, the Slade said: "Margaret worked closely with a number of tutors and made a positive and enthusiastic contribution to the life of the Slade.

"The news of her untimely death came as a great shock.

"She will be missed by staff and students and UCL wishes to extend its condolences to her family."