“Some [of the groups] have disappeared while others have been added,” said Palle Nilsson, head of intelligence at Stockholm police.

According to the report, a total of 20 of the identified gangs were new while 30 had been noted in previous such reports.

The total number was up from 46 in 2017 and 39 identified in 2015. The updated survey was carried out in order to ensure police have a comprehensive picture of the gangs active in the region, and to understand each gang's capabilities.

Police said that around 1,500 people were involved in criminal networks across Stockholm, and that the number of women involved had increased since earlier reports from 2015 and 2017. Women were also reported to have taken on more roles linked to planning and carrying out crimes, as well as simply supporting the groups.

The average age of those involved in the gangs had fallen, with most networks including members ages under 16 years old. Over the same period, more women have taken on roles within these gangs, according to a report from Stockholm police.

And the report also noted increased mobility among the groups, with people more likely than in previous years to be part of multiple networks or to switch, and “a clear trend towards collaboration with other criminal networks, nationally and internationally”.

Many of the gangs have access to weapons.

Some 15 people have been fatally shot in Stockholm in the first nine months of 2019 alone, and the report also noted that gangs were more likely to turn to kidnapping than in previous years.

“Further conclusions are that several of the networks have a high level of violence and we see that the average age of those in the networks has dropped. In addition, we see that women are more involved in organized crime than before,” said Palle Nilsson.

IN DEPTH: What's behind the rise in gang violence across Sweden?