In Germany, police raided 100 on Monday.
Among other things, a person who is considered a "drug chef" was arrested, according to the newspaper Bild.
In the Netherlands, several strikes were made, including against a drug lab.
According to information to SVT, the raids around Europe are linked to an attack on a number of Swedish addresses on Monday morning.
Among other places in Stockholm, Gothenburg and Helsingborg.
- Yes, it is true that the police have made efforts in several parts of the country today, but we can not comment more than that.
We do not comment on ongoing efforts, says Karin Styrenius, spokesperson for the police's National Operations Department.
A source tells SVT that the Swedish police have played an important role in international cooperation and that the government has been informed about the operation.
- It is a very hard blow against gang crime in Sweden, says a source.
German Bild reports that the operation was initiated by the US FBI and that the suspects were tracked through cracked encrypted chats, similar to the Encrochat operation.
On Tuesday morning, Europol will hold a press conference on the operation.
- Swedish police will participate, where we will tell more, says Karin Styrenius.
The text is updated.