An Egyptian Christian has been killed and at least five other people wounded in a shooting on a train travelling between Cairo and Assiut in southern Egypt, sources have said.
It was not immediately clear if Tuesday's shooting was motivated by religious issues in the Muslim majority country, where tension between the two communities has risen after the New Year's Eve bombing of a church in Alexandria that killed 23 people.
Security officials said the armed man boarded the train at the town of Samalout in the central Minya province and opened fire on the passengers.
The train originated in Assiut, home to a substantial Christian community and a famous monastery.
Police arrested the man as he tried to flee the scene, according to the officials.
Egypt's official news agency said one person was killed and five others wounded in a "random shooting".
The report did not identify whether those hurt or killed were Christians. A security source confirmed one had been shot dead.
However, Mariam Salah, a doctor in Minya, south of the capital, told the Reuters news agency that her hospital was treating five wounded Christians.
Concern for Christians
Ayman Mohyeldin, Al Jazeera's correspondent in Cairo, said that the authorities are keen not to jump to conclusions about the motivation of the attack.
"The January attack is fresh on everyone's mind. There are going to be a lot of questions whether it [Tuesday's shooting] was religiously motivated," he said.
The incident comes as Egypt faced expressions of concern from the international community over the safety of its Christian population and recalled its ambassador to the Vatican following comments by Pope Benedict XVI.
In a speech on Monday, Benedict cited recent attacks on Christians in Egypt, Iraq and Nigeria, and said governments must take effective measures to protect religious minorities.
Hossam Zaki, a spokesman for Egypt's foreign ministry, described Benedict's remarks as "unacceptable'' and charged him with interfering in the country's internal affairs.
Hosni Mubarak, Egypt's president, has repeatedly said that the government will do its utmost to protect Egypt's Christians and has accused foreign groups of being behind the New Year's Eve church bomb.
The church attack reopened long festering wounds in a Christian community that often says it feels like second class citizens in its own country due to widespread discrimination.
Coptic Christians demonstrated around the country, including in Assiut, in the aftermath of the bombing and called for better protection and equal rights.