A senior leader of the Greek Orthodox Church has been killed along with 16 other people in a helicopter crash off the coast of northern Greece.

Patriarch Petros VII of Alexandria, the spiritual leader of Greek Orthodox Christians in Africa, was heading north from Athens when contact was lost.

He was going to a monastic community on Mount Athos for a religious event.

Aircraft and ships mounted a rescue operation which located wreckage and bodies in the nearby Aegean Sea.

No cause has yet been established for the crash, which occurred when conditions were good.

'Huge loss'

Military officials said the helicopter was in a good condition and the pilots were experienced.

The Patriarch, 55 - one of the most senior figures in the Greek Orthodox Church - was on a visit to Greece from Egypt accompanied by Orthodox priests and laymen from the Alexandria area.

His helicopter went missing about two hours into the flight from Athens to Mount Athos - known as the Holy Mountain - for a religious ceremony.

A church spokesman said the death of Patriarch Petros was a huge loss as he had breathed new life into the Orthodox Church in Africa since being elected seven years ago.

Mount Athos - a male-only community of Orthodox monasteries - has been a centre of Eastern Orthodoxy since AD963 and is classed as a semi-autonomous monastic republic.