People fleeing a gunman in Kraków ran into nearby churches for shelter during a shooting in the Polish city's historic centre on Saturday.
Polish church leaders have called for prayer and solidarity after six people were killed in the attack, including a British national.
The 24-year-old suspect, identified as Michał Oksiński, died in hospital on Monday after being shot by police and taken into custody.
Speaking to Premier Christian News, Fr Leszek Gęsiak SJ, spokesperson for the Polish Bishops' Conference, said the country was in a state of shock.
“Never, ever in Polish history have we experienced this kind of terrorist attack,” he said. “Poland was a place where people could live quietly, without any problems, without any terrorist attacks. So the people, and not only in Kraków but the whole country, are absolutely shocked.”
The shooting took place in the city's Main Market Square, a popular tourist destination just steps from St Mary's Basilica.
Fr Leszek who lives around 600 metres from the square, said the attack was particularly distressing because of the number of people enjoying the area at the time.
“It was Saturday evening. Many people were in the cafés, taking coffee, walking, just chatting. There were families and groups who had come from other countries,” he said.
Cardinal Grzegorz Ryś, Archbishop of Kraków, urged residents to stand together following the attack. In a letter on 7 November, he said: “We do not want to, we cannot, we are unable to be indifferent at such a moment. We want, we need and we must be together.”
He also invited people to attend a special Mass at St Mary's Basilica for those killed and injured, and their families.
Fr Leszek said the service, held close to the scene of the shooting, offered an important opportunity for the Christian community to come together.
“It's important for us Christians that this event has united us as a nation, as a Christian community, as a Catholic community,” he said.
Reflecting on Cardinal Ryś's message during the Mass, he added: “We cannot understand what has happened. Sometimes we cannot understand some decisions of individual people, but we have belief and confidence in God.
“In these terrible moments, we cannot lose hope or the feeling that we are united in Christ. That's what can help us survive this very difficult, also spiritually difficult, moment in Poland.”
The Church has also offered practical and psychological support to those affected. Fr Leszek said people had taken refuge in three nearby churches during the shooting as they tried to escape the violence and find somewhere safe. He said churches and other services were now offering help to those who needed it.
Investigators are continuing to establish the gunman's motive. Government ministers initially suggested he may have been influenced by far-right ideology, but officials have since urged caution, saying there is not yet enough evidence to reach a conclusion.
Prosecutors said a Gadsden flag, associated with freedom and rebellion, was found in the suspect's room, but stressed that its presence did not establish an extremist motive.
Police have also detained five people over online posts glorifying the attack, amid concerns about possible copycat incidents.
Fr Leszek urged people to pray particularly for those who died, their families and those still recovering in hospital.
“We are praying first for the victims. We also pray for the policemen, the two police officers who were acting directly and could stop the attacker,” he said.
“We are praying also for the families of those who died, and for hundreds of people who were at that moment in the market square, who have experienced terrible shock and psychological trauma.”
President Karol Nawrocki declared two days of national mourning on 8 and 9 November, while the government has said it will review regulations governing firearms permits.
