A dual Swiss-Spanish national has been arrested in Morocco for alleged involvement in the killings of two Scandinavian tourists.
The man, who has not been named, was detained in Marrakesh for allegedly trying to recruit Moroccans "to carry out terrorist plots", a statement said.
Louisa Vesterager Jespersen, 24, from Denmark, and Maren Ueland, 28, from Norway, were murdered in December.
Their bodies were found in the High Atlas mountains near a tourist spot.
Norwegian police have said a video appearing to show one of the tourists being beheaded was likely to be real.
Morocco's Central Bureau for Judicial Investigations said on Saturday the Swiss-Spanish national was suspected of "teaching some of those arrested... about communication tools involving new technology and of training them in marksmanship".
The Swiss-Spanish national followed an "extremist ideology", the statement said.
Police said four main suspects in the killings had pledged allegiance to the Islamic State group, although investigators believe there was no contact with groups in Syria or Iraq.
In the capital Rabat a minute's silence was held with Danish and Norwegian diplomats present, while hundreds more people attended a vigil in the southern village of Imlil, near where the women's bodies were found.
Flowers were also laid in the city of Marrakesh.
Who were the victims?
Ms Jespersen, who was 24 and from Denmark, and 28-year-old Norwegian Ms Ueland had been studying outdoor activities at the University of Southeastern Norway.
They had arrived on a month-long holiday in Morocco on 9 December and had travelled to the foothills of Mount Toubkal, North Africa's highest peak, 10km (6 miles) from Imlil.
Their bodies were found in their tent.
Both women had taken full precautions ahead of their trip, Maren Ueland's mother said.