OSLO (Reuters) – Norway will allow travel to and from Finland, Iceland and the Swedish island of Gotland from Monday, but maintain travel restrictions on mainland Sweden due to its higher level of COVID-19 cases, amid concerns of a second wave of infections.

Denmark, Finland and Norway have lifted some of the controls on leisure travel they imposed to slow the coronavirus pandemic, but have kept most of those imposed on Sweden, the richest and most populous of the Nordic countries.

Leaving most of Sweden out of the arrangements breaks with long-standing close cooperation between the Nordic countries, and goes against the wishes of the European Commission, which wants to lift by Monday the internal borders in the Schengen travel zone, which in normal times are open.

Norway is not a member of the EU but belongs to Schengen.

“I think we need to be honest and say that in the Nordics this is something of a difficult issue at the moment,” Norwegian Prime Minister Erna Solberg told a news conference.

“At the same time we have a good conversation about how we’re doing it, and the fact that we’re applying objective criteria has been met with understanding.”

Swedish Home Affairs Minister Mikael Damberg said his government would continue to work on opening up the whole of the Nordic region. He said a rise in coronavirus cases reported in Sweden in recent days was the result of increased testing.

“That means we are going to see an increase in the number of cases with mild symptoms, but it does not mean that there is a greater rate of infection,” he said in a written comment to Reuters.

Norway’s arrangements add to the patchwork of bilateral travel arrangements various European countries have made as they emerge from lockdowns.

Norway will assess the public health situation of each region in the Nordics separately and will review its travel advice every fortnight, starting June 15, Solberg said.

Gotland, a Baltic island with close to 60,000 inhabitants, is the only Swedish region Norway will allow Norwegians to travel to without having to undergo a 10-day quarantine on their return. Swedish travellers from Gotland will be allowed to travel to Norway without undergoing quarantine.

Sweden adopted fewer restrictions during the pandemic and by June 10, Sweden’s COVID-19 deaths were 4,717 – four times that in the other Nordic countries combined.