NEW DELHI — A young man was mauled to death by a white tiger at the New Delhi zoo on Tuesday after he fell into a moat in the animal’s enclosure and was unable to climb out to safety, witnesses said.

The man, identified by the police as Maqsood Khan, 20, was spotted by other visitors, but the security personnel who came to the scene were not equipped with tranquilizer guns.

Anil Kumar, a police spokesman, said Mr. Khan was in the enclosure at the National Zoological Park for 10 minutes before he was killed. Photographs showed Mr. Khan several feet from the tiger, his hands folded as if in prayer.

Bystanders with cellphones took images of Mr. Khan cowering in the moat, the tiger pawing at him and later seizing him by the neck and lashing his body back and forth, finally settling in a grassy corner with its prey.