An off-duty policeman has opened fire on a train in Egypt, killing a Christian man, but it is unclear whether the attack was sectarian.
At least another five people were reported to have been injured in the shooting on a train between Assiut and Cairo.
Officials said at least four of those hurt were Coptic Christians.
Witnesses said hundreds of Christians later clashed with police outside the hospital where the wounded were taken.
Police fired teargas to disperse them, reports from Samalut, in Minya province, said.
Tensions between Muslims and Christians in Egypt have been high following a bomb attack on a Coptic church in Alexandria at the new year that killed 23 people.
The gunman, who officials said had boarded the train at Samalut, has been arrested.
The Egyptian interior ministry named him as police officer Amer Ashour Abdel-Zaher. Officials have not given a motive for Tuesday's shooting.
The ministry statement said the officer "opened fire on some train passengers from his pistol and ran away", adding that he was later arrested at his home.
One of those injured was reported to be the dead man's wife.
Egypt's Coptic Christian minority is estimated to make up about 10% of Egypt's 80 million people, who are mostly Muslim.