A vigil was held in Rome's St Mary in Trastevere church
Turkish newspapers fear the murder of an Italian priest in the northern town of Trabzon on Sunday may have damaged Turkey's standing in the eyes of the world.
Some commentators hope the killing is not linked to the furore in the Muslim world over the cartoons satirising the prophet Muhammad.
In Italy, some papers say the murder may be an obstacle to Turkey's EU accession.
OKTAY EKSI IN TURKEY'S HURRIYET
This murderer has not only taken a life. He has also ruined Turkey's credibility, which had already been damaged. Our conviction record already includes an attempt on the Pope's life by a Turk. Now Catholic priest killed in Turkey has been added.
EMIN COLASAN IN TURKEY'S HURRIYET
If the priest in Trabzon was killed because of the cartoons, it means we have sustained another new and incurable wound to our credibility.
TAHA AKYOL IN TURKEY'S MILLIYET
Thank God, the protests in Turkey [over the cartoons] managed to take place in a mature manner. However, a 'youth' murdered Father Santoro in Trabzon. I hope this murder is not a sign of a contagious disease.
MEHMET ALI BIRAND IN TURKEY'S POSTA
We are not the kind of society to show its reaction by killing an innocent priest. I condemn the person who committed this murder... Those who close the doors and dream about an inward-looking Turkey - all fundamentalists - and those who make religion a tool of policy are the ones really responsible for this event.
VATICAN NEWSPAPER OSSERVATORE ROMANO
The killing of Don Santoro by all means fits into the climate of tension of recent days. Faced with such acts, we are shocked and saddened, but we must also recognise a sign of irrepressible hope: some of our brothers are willing to spend their lives trying to build bridges between two shores which are still far apart. Father Santoro was one of them.
EDITORIAL IN ITALY'S CORRIERE DELLA SERA
What really makes one think is the potential international repercussions: slower, less emotional, but long-lasting. The fact that the killing happened in Turkey is serious. It is a strategic ally of the West and the next and most cumbersome EU entry candidate.
ANTONIO FERRARI IN ITALY'S CORRIERE DELLA SERA
Father Santoro's assassination, the motives for which are as yet unclear, may well become one more obstacle on the long and difficult path leading to EU membership.
ALBERTO PASOLINI ZANELLI IN ITALY'S IL GIORNALE
Reflections about 'solidarity' among the faithful of other religions are comprehensible. But what has happened to Don Santoro and, before him, to many other Catholic or at least Christian priests in different countries of the Middle East in the past few years clearly indicates the limits of this 'solidarity'.
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