BRATISLAVA, Slovakia – Starting Friday, Slovakia will require travelers from any country to quarantine on arrival unless they are vaccinated against the coronavirus.

Slovakia is gradually reopening dozens of border crossings previously closed amid measures to contain the delta coronavirus variant. The measure became effective on Monday. Slovak authorities are tightening border checks at the remaining crossings to enforce the travel restrictions.

Some 30 crossing have been closed, drawing protests at home and in neighboring countries, which include EU members Czech Republic, Poland, Austria, Hungary and Ukraine. All people traveling to Slovakia from any country must register online before they cross the border.

Slovakia registered 45 new coronavirus cases on Tuesday.