Swedish government officials have accused the US Embassy in Stockholm of conducting unauthorized surveillance activities in the country, shortly after similar charges were made in Norway and Denmark.

The surveillance, performed by people “assigned by the [US] embassy to undertake the measures,” has been in place since 2000 and its extent is still unknown, Swedish Justice Minister Beatrice Ask said on Saturday.

“It seems as though we haven’t been fully informed and that’s not good,” AP quoted her as saying.

Ask called on US officials to cooperate in the investigation into the matter.

She did not disclose the targets of the surveillance but pointed out that the activities “seem to be similar” to those uncovered in Norway earlier this week.

“We welcome that those countries that have a heightened threat risk apply their own measures to reduce the risk for attacks, but of course it has to be done in line of what the Swedish law says and permits,” Ask noted.

Denmark’s TV-2 Denmark disclosed on Saturday that the US Embassy in Copenhagen has also conducted secret surveillance activities in the Danish capital.

The report says a unit of 14 agents attached to the US Embassy kept tabs on Danish citizens by adding their personal data to a special computer database.

Also on Wednesday, Norway’s TV-2 News channel revealed that the US Embassy in Oslo has hired 15 to 20 people to monitor local residents.

Following the disclosure, Oslo asked US officials to provide an explanation.