A policing operation aimed at protecting women in Londonderry after two weekend attacks were reported will continue for "as long as it has to," police have said.

On Friday night a woman was assaulted at knifepoint in Drumahoe, while on Saturday afternoon a woman walking her dog in Top of the Hill was approached by a man holding a kitchen knife.

Police are investigating whether the same man was involved in both incidents.

PSNI Ch Supt Gillian Kearney said "increased, high visibility" patrols are to continue "to make sure people feel reassured and supported across the district".

She said the extra policing would continue for "as long as it has to, to make sure people feel reassured and supported across the district".

Speaking to BBC Radio Foyle's North West Today programme, Ch Supt Kearney, the city's most senior police officer, said police understand the most recent attacks, will cause great concern in the community.

"I want to reassure people that we have a focused patrolling plan, including high visibility, increased police presence in keys areas, such as our local parks and the city centre, and that will continue over the coming days," Ch Supt Kearney said.

Both parks where the attacks took place are in the city's Waterside and about 2.5 miles apart.

At a press conference in the city on Monday afternoon, Ch Supt Kearney said the investigation is "progressing at pace", adding that police are "following a number of lines of enquiry".

"If you notice someone acting suspiciously or if someone's behaviour causes concern do not approach, but contact police immediately," she said.

Nicki Sheller-Cullen walks her dogs in both parks where the attacks took place.

She said she had initially thought twice about walking at Top of the Hill on Monday.

"After I heard about the attacks, I have to say I was very frightened to come up here on my own," she told BBC News NI.

"But at the same time I like coming up here, I like walking my dogs up here and I can't live my life in fear. I thought, I am still going to go on my walk, but I will just be on my guard. I couldn't really relax... without a doubt it is very scary."

Earlier, Ch Supt Kearney told BBC Radio Foyle there is no link between the two weekend attacks and earlier attacks in the city at the end of last month.

"We have across Derry city and Strabane experienced a reduction in violence against women and girls incidents. But what is of particular concern is how unusual these two incidents reported at the weekend are."

Ch Supt Kearney said police had carried out an operation aimed at identifying "people displaying concerning or predatory behaviour" over Halloween.

She said that operation was "very successful."

A rally highlighting women's safety is due to take place in Derry on Friday.

Speaking in the Assembly, SDLP Foyle MLA Sinéad McLaughlin called for the Executive's framework for ending violence against women and girls to be accelerated.

"We need comprehensive, well-funded support systems that ensure shelters, hotlines, counselling and legal services are accessible to every single survivor," she told MLAs.

"This is a moment that calls for a strengthened response and an unwavering commitment to change.

"We must take a clear stand - violence against women and girls is unacceptable."

Meanwhile, Democratic Unionist Party (DUP) Foyle MLA Gary Middleton, described the weekend attacks as "terrifying [and] grotesque".

"The perpetrator or the perpetrators remain at large and must be brought to justice immediately," he told the Assembly.

"Someone, somewhere must have information."

Police have appealed for anyone with information about the weekend attacks to come forward.