The industrial action occurred after the Swedish Dockworkers' Union did not manage to secure a deal with harbour owners on union representation, according to The Local news outlet.
"[The strike] is not something we want, but we haven't been able to find any other solution", the union’s representative in Malmo, Henrik Collvin, said as quoted by the media.
The strike has paralyzed the movement of goods in Malmo, Gavle, Helsingborg, Holmsund, Karlshamn, Sundsvall, Soderhamn, and Umea. It is set to take place in Stockholm and Gothenburg later on 23 January.
In 2016, some 350 Swedish pilots of the Scandinavian SAS airline walked out in protest after talks between work unions and the SAS ended with no solution.