The prime ministers of Sweden, Denmark and Finland on Saturday visited a global gathering of scouts to show support for youth after attacks last month killed many teenagers in Norway.

Sweden's Fredrik Reinfeldt, Denmark's Lars Loekke Rasmussen and Finland's Jyrki Katainen travelled to Rinkaby, in southeastern Sweden, where some 39,200 scouts from 146 countries were partaking in the 22nd World Scout Jamboree.

"It's a fantastic possibility to see cross-border meetings between youth. It's even more important now after what happened in Norway has left an impression and weighed down on us," Reinfeldt said, quoted by Swedish news agency TT.

"The purpose of the joint visit is to show support for youth activities and international cooperation between young people after the tragedy in Norway," Katainen's office said in a statement released before the visit, which noted scouting supported "the development of young people as active and responsible citizens."

In an op-ed published Saturday in major dailies in their respective countries, Reinfeldt, Loekke Rasmussen and Katainen said the Nordic countries would continue to collaborate to fight extremism.

"Together we stand up for young people's community involvement and our countries' welfare and safety," they said.

"We will now continue to develop our Nordic social model ... It is our most important remedy in the fight against anti-democratic messages, extremism and the use of violence," they added.

Sweden's King Carl XVI Gustaf and his wife Silvia visited the scout gathering on Friday.

This year's jamboree took place under tightened security after Anders Behring Breivik, a Norwegian rightwing extremist, gunned down 69 people, many of them teenagers, taking part in a summer retreat run by Norway's ruling Labour party on July 22.

Hours before he killed eight people by setting off a bomb near the offices of the Labour-led government in central Oslo.

The jamboree was ending Saturday, after 12 days during which the scouts -- aged 14 to 17 -- camped, made their own food, took part in discussions on the theme of solidarity and played music among other activities.