A knife-wielding car thief has targeted one of Northern Ireland's most prominent female politicians in the latest in a string of similar attacks on women in Belfast.

Anna Lo faced down a youth in his early teens armed with what she described as a six-inch kitchen knife who demanded the keys of her car outside her office in the south of the city.

The diminutive 61-year-old said she refused to give the teenage attacker her keys, before he fled the scene of the attempted robbery at University Street at around 1pm on Friday.

But after a number of women were targeted in a spate of so-called car-jackings in Belfast, she advised others fearing for their safety to give the thieves their car, rather than risk injury.

"I think he recognised me and ran away," said the Alliance Party's Stormont representative for South Belfast, who estimated her attacker could be as young as 11 to 14 years of age.

"I had left a bag and my handbag behind the driver's seat and as I straightened up out of the car, he was behind me. He had a big kitchen knife - this was not a pen knife - I would say it was a six-inch kitchen knife."

She said he demanded her keys, but when she refused to hand them over there was a brief stand-off, before the would-be thief ran off through a nearby alleyway. The Assembly member said she got into her car and drove a short distance, before stopping to dial 999.

She said the youth was wearing a black hooded top, was of slight build and around 5ft 5in. "I am not the only person that has suffered such an ordeal and my thoughts continue to be with anyone who has suffered at the hands of those involved in such acts," she said.

"This incident serves to highlight the need for everyone to be vigilant in relation to car-jackings. We need to have those behind such acts brought to justice.

"I am speaking out to highlight this very troubling issue which has come to prominence in recent times."