Pilgrims travelling to Poland for World Youth Day will need to pack their passports after the Polish Government announced a temporary suspension of the Schengen passport-free zone.
The Interior Minister, Mariusz Blaszczak, said the checks introduced on 4 July will continue until 2 August. He said travellers from within the Schengen area should bring their passports or other ID documents and others should carry their Polish visas.
Checks will be carried out at airports, seaports and on borders with other European Union states, including Germany, the Czech Republic and Slovakia.
An agreement allowing residents of Ukraine and Russia's Kaliningrad exclave to travel 50 kilometers (31 miles) into Poland has also been suspended. The Poland-Russia local border traffic agreement has been in place since 2012 and covers Kaliningrad and parts of Poland's northern and north-eastern provinces of Pomorskie and Warminsko-Mazurskie.
Poland routinely introduces border controls during big events, but security has been heightened further following terror attacks in Europe.
“The move is designed to ensure better security during the Nato summit 8-9 July and the Roman Catholic Church’s World Youth Day event 26-31 July,” organisers for World Youth Day said in a statement on the official website.
The statement said officials had announced that checks would be carried out randomly “on the basis of risk analysis and information provided by the security services of other countries”.
Over 3,000 Catholics from Great Britain are expected to travel to Krakow for the youth event. Pope Francis arrives in Poland on Wednesday 27 July to meet President Andrzej Duda, and joins the pilgrims on Thursday, where he will deliver his welcome address.