Moroccan authorities have arrested a Swiss-Spanish national in connection with the killing of two Scandinavian women, the counter-terrorism agency have said.

Louisa Vesterager Jespersen, 24, from Denmark, and Maren Ueland, 28, from Norway, were found dead on December 17, near the village of Imlil in the Atlas Mountains.

The pair had set up camp at an isolated mountain site around two hours from the tourist village of Imlil when they were attacked.

Louisa Vesterager Jespersen, 24, was found beheaded at a campsite in western Morocco last week. Moroccan authorities have arrested a Swiss national in connection with the killing

Maren Ueland, 28, was found dead alongside her. A video purporting to show the women being killed has been circulated by extremists online

Video purporting to show the attack has been circulated on ISIS forums, and shows one man brandishing a large knife saying in Arabic 'it is Allah's will'.

The man arrested on Saturday is also suspected of 'involvement in recruiting Moroccan and sub-Saharan nationals to carry out terrorist plots in Morocco against foreign targets and security forces in order to take hold of their service weapons', the Central Bureau for Judicial Investigations (BCIJ) said.

Nineteen other men have been arrested in connection with the case, including four main suspects who had pledged allegiance to Islamic State in a video made three days before the tourists' bodies were found.

Nineteen other men have been arrested in connection with the case, including four main suspects who had pledged allegiance to Islamic State in a video made three days before the tourists' bodies were found

Police and domestic intelligence spokesman Boubker Sabik this week described the four men as 'lone wolves', and said 'the crime was not coordinated with Islamic State'.

Ms Ueland and Ms Vesterager Jespersen, who were studying to be outdoor guides at a Norwegian university, were spotted with three men in Marrakesh before heading to the Atlas mountains to hike.

They had been travelling around the country as part of a month-long trekking holiday.

Last week hundreds of people from Malen's hometown of Bryne turned out to hold a candlelit vigil, including her friends and family members.

A portrait of Louisa and Maren are seen at a supportive event, among flowers and candles, in Town Hall Square in Copenhagen, Denmark

It was emphasised that the event was not a memorial, but a way to show support and compassion to Malen's loved ones.

'It's important to stand together and be important for people to show solidarity,' Thor Inge Sveinsvoll, manager of the Rogaland county Red Cross, told Norway's Aftenposten.

'We want to show that we care about each other, and that we are together for a kinder world,' said Odd Ivar Nese, one of the organisers.

It has also emerged that the two women were 'happy and sociable' in their final days, according to Rachid Imerhade, a mountain guide who had met the two friends a few days before their deaths.

People gather to pay tribute to the victims in front the St. Peter's Cathedral in Rabat, Morocco

He said: 'They were smiling, chatty and sociable. They talked a lot with the other people around.'

Jespersen's mother, Helle Petersen, told the Danish newspaper B.T. that her daughter was 'always happy and positive. Everyone loved her and she saw the best in everyone'.

Compared with other countries in North Africa, Morocco has been largely insulated from militant attacks.

The most recent took place in April 2011, when 17 people were killed in the bombing of a restaurant in Marrakech. In 2017 and 2018, Morocco said it dismantled 20 militant cells planning attacks in the country.