MALMÖ, Sweden - Sweden reinstated border controls on Thursday in a bid to gain control over the massive influx of migrants arriving in the country, without blocking the steady flow of asylum seekers.

On Thursday at 12:00 pm (1100 GMT), police began carrying out identification checks on passengers travelling on trains crossing the bridge over the Oresund strait from Denmark, an AFP correspondent reported.

Police were also checking papers at at terminals for ferries arriving in southern Sweden from Denmark and Germany. Those are the routes most used by migrants.

“This is not a fence. We need to make sure that we have control ... We have to make sure we know who is coming to Sweden,” Prime Minister Stefan Lofven insisted.

“Introducing border controls is not to prevent people from coming to Sweden to seek asylum,” the head of the Swedish Migration Agency Anders Danielsson meanwhile told Swedish news agency TT.

“On the contrary. They will have their case heard, but we need to (regain) control,” he added.

Sweden, a country of 9.8 million people, has taken more refugees as a proportion of its population than any other country in Europe as the continent struggles with its worst migration crisis since World War II.

The Scandinavian country expects to receive up to 190,000 asylum seekers this year - the equivalent of 1.5 million people arriving in a country the size of Germany.

The massive influx has strained Sweden’s capacity to take care of the new arrivals, with authorities recently warning they were no longer able to provide housing for them.

“People are forced to sleep in tents, in offices and in evacuation centres” normally used for natural disasters, Migration Agency spokesman Mikael Hvinlund said.

“We are not fulfilling our mission, which is to offer a roof to everyone... Re-establishing border controls can help us,” he said.

People arriving in Sweden without valid identification documents would be allowed to seek asylum, but those who do not want to do so - for example those who simply want to transit through Sweden - would be refused entry.