A delegation of religious leaders representing the world's major faiths has visited Ukraine in a pilgrimage of solidarity.
The delegation included the former Archbishop of Canterbury, Lord Williams, the Archbishop of the Orthodox Church of the UK, Metropolitan Nikitas Lulias, Grand Mufti Mustafa Ceric and other representatives of Islam, Judaism, Hinduism, Buddhism and Christianity.
The historic pilgrimage was organised by the Elijah Interfaith Institute and saw religious leaders visit refugee camps and the city of Chernivtsi.
A letter from the Pope was read out during a visit to the city's main theatre in which he said it was incumbent on the world "not to remain indifferent before the violence of Cain and the cry of Abel, but instead to speak out forcefully in order to demand, in the name of God, the end of these abominable actions".
"The present moment leaves us deeply troubled, because it is marked by the forces of evil," said Pope Francis.
The delegation also visited Poland and Romania, where many Ukrainians have fled.
Commenting on the pilgrimage, Lord Williams said he was inspired by the response of faith communities.
"We were deeply touched by the faith and patience of the people we met in the refugee centres we visited in Chernivtsi," he said.
"There was a very clear commitment among the refugees themselves to helping one another, to welcome new arrivals and make them at home as much as was possible after terrible and traumatic experiences - about which we heard many harrowing stories; and there is a massive mobilisation of volunteer groups to handle the constant stream of people fleeing from the Eastern part of the country.
"The churches are very visible in this, as is the historic and important Jewish community of Chernivtsi, one of whose synagogues hosts a refugee centre.
"The event of reflection and witness which we took part in was intense and inspiring. Many speakers underlined the fact that the Russian aggressors were doing profound damage to themselves as well as to their victims, and the message from the Pope that was read out made the same point.
"It was his most forthright condemnation yet of the violence. Many calls were made for the Orthodox church in Russia to support a ceasefire over the Easter/Passover season. It was altogether a very challenging but immensely enriching visit. As is often said, if you want to see Christian hope at work, go where the situation is hardest."
The pilgrimage was the co-initiative of James Sternlicht, founder of the US non-profit, the Peace Department, and Rabbi Alon Goshen-Gottstein, founder of the Elijah Interfaith Institute.
Sternlicht said, "In this moment, in a world gripped by profound darkness, we must unite to heal humanity."
Rabbi Goshen-Gottstein added, "This is the first time ever that an interfaith delegation has undertaken a mission of friendship in entering a country at war.
"This is all the more remarkable considering the high level of the religious representatives who are combining forces to provide solidarity and comfort in this time of conflict."