Turkish leaders said the killing of a Catholic priest appeared to be the work of a lone gunman, but also signalled fears of a possible link with the rage sweeping the Muslim world over cartoons of the Prophet Mohammad.
Police have issued a sketch of the gunman who shot Andrea Santoro, a 61-year-old Italian, while he was praying in his church on Sunday in the Black Sea city of Trabzon.
"We strongly condemn this incident...We believe it is the work of one individual. His motive should become clear in due course," Foreign Minister Abdullah Gul told reporters.
A Vatican embassy spokesman in Ankara quoted witnesses as saying the gunman, believed to be 16 or 17 years old, shouted "Allahu Akbar" (Arabic for "God is greatest", a common Muslim chant) as he shot Santoro.
Violent attacks on Christian clergy are virtually unheard of in Turkey, which views itself as a bridge between mainly Christian Europe and the predominantly Muslim Middle East.
Prime Minister Tayyip Erdogan twinned the shooting with the anger rocking the Muslim world over cartoons published in Denmark and reprinted in other European newspapers caricaturing Islam's Prophet, saying both could be seen as examples of intolerance.
"(The shooting) is extremely regrettable, especially after the recent developments in Denmark," NTV commercial television quoted Erdogan as saying.
"Above all, nothing about entering a place of worship to kill a priest is acceptable," he said.
Turkey, with a population of about 72 million, is overwhelmingly Muslim and has a Christian population of more than 60,000.
Pope Benedict expressed his sorrow over Santoro's death.
"I share the pain of the entire Church of Rome for the grave loss of such an esteemed and conscientious priest," the Pope said in a statement. "I hope that his spilt blood becomes a seed of hope to build an authentic brotherhood between people."
The Vatican has joined Muslim countries, including Turkey, in condemning the cartoons of the Prophet, saying freedom of speech did not mean freedom to offend a person's religion.
Turkey's non-Muslim clergy, including Istanbul-based Ecumenical Patriarch Bartholomew, spiritual head of the world's Orthodox Christians, have also condemned the cartoons, which were first published in a Danish newspaper.
"If mocking religious feelings is an act of gross irresponsibility...fanatical violence against symbols and people is also blasphemous," Italian Prime Minister Silvio Berlusconi said in a statement.
"It is precisely the wish not to give in to intolerance that means we will continue to work to keep open the dialogue between religions and between civilizations, to isolate and defeat violence and those who preach it," he said.