European Commissioner for Home Affairs, Cecilia Malmström, said she was open to discussing the matter with Denmark, but according to AFP, she warned that authorities must "refrain from taking unilateral steps and make sure that any measures taken are in line with the relevant law."
Denmark and Sweden are both members of the Schengen area, a group of 25 European countries that allows people to travel freely among them without passing through typical border controls. Some 20,000 people commute to work over the Öresund bridge, which connects the Danish capital of Copenhagen to Sweden's southern city of Malmö, every day.
Denmark, where anti-immigrant sentiment has been gaining political clout, announced earlier this week that it wants to bring back its border controls in order to prevent drug-trafficking and other cross-border crimes. AFP reports that Danish integration minister Soren Pind has denied that the goal is to check passports.