Pilgrims will be subjected to random stop and searches, including personal luggage at all major events put on for World Youth Day in Krakow after a weekend of terrorist atrocities in Germany, which shares a border with Poland.
The checks, using mobile x-ray devices, handheld metal detectors, and dogs trained to detect explosives, will be carried out at railway and bus stations and major road and transport hubs, as well as anywhere a crowd has gathered, according to the organisers of World Youth Day 2016.
And Polish authorities have banned any trucks or lorries from entering any area where pilgrims are gathered unless it is pre-approved by World Youth Day organisers after a truck was driven into a crowd of revellers celebrating Bastille Day in Nice, in France earlier this month.
The British Embassy in Warsaw has warned pilgrims that they should expect long delays at border crossings and expect delays at every event and in the main focus points of World Youth Day, but that the terrorism threat as a whole in Poland is "low".
Despite there being no specific security threats in Poland ahead of Pope Francis' arrival in the country on Wednesday Polish authorities have expressed concern after a 48-year-old Iraqi man was charged with possessing trace amounts of explosives. The man - who has recently been expelled from Sweden - was arrested and charged in Lodz, which is 140 miles away from Krakow.
Prosecutor Beata Marczak told reporters that the man was charged on Sunday with "possessing trace amounts of explosive material". The offence carries a maximum term of eight years in prison.
"That does not mean we found enough explosive material to cause an explosion," she added, "There are no grounds for charging him with participating in terrorist activity."
However, satellite news channel Polsat News has reported today that the explosive traces that were allegedly found on the man's luggage and clothes at hotels in Lodz and Krakow.