The zoo was full of visitors when the man entered the lion's den

A Ukrainian of Azerbaijani origin lowered himself into the enclosure using a rope. He was quoted as saying God would save him.

One of four lions in the enclosure seized the 45-year-old by the throat, and he died at the scene.

The zoo - which keeps the lions on an "island" protected by concrete blocks - was packed with visitors at the time of the attack on Sunday.

"The man shouted 'God will save me, if he exists', lowered himself by a rope into the enclosure, took his shoes off and went up to the lions," a zoo official told Reuters news agency.

"A lioness went straight for him, knocked him down and severed his carotid artery."