In response to the European migrant crisis the Swedish government mandated ID checks on all trains coming from Denmark from December 2015. As checks performed by the Swedish police took up to 20 minutes per train, timetables were severely disrupted. Beginning on 4 January 2016, transport operators would be fined if any improperly documented people were found to be brought into Sweden. As a result, DSB restructured the timetable, constructed a fence between the platforms at CPH Airport station, and introduced its own ID checks in order to gain entrance to the Malmö-bound platform at CPH Airport station. The frequency of trains across the bridge has been reduced to a maximum of 3 tph. Apart from the reduced frequency, services from Sweden to Denmark run as usual to Helsingør during the day and Østerport in the evenings, with no ID checks entering Denmark. Since 4 May 2017 the line had changed to perform ID checks only at Malmö Hyllie station for trains travelling to Sweden. To travel from København H to CPH Airport, passengers could use the Copenhagen S-trains or the 3tph shuttle between CPH Airport and Nivå (which runs to Helsingør at a lower frequency in the evenings when trains from Sweden do not go farther). This shuttle reverses on the Danish-bound platform at CPH Airport, and maintains a 6tph service north of København H.