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. In interviews with NDTV, a cable news channel, witnesses complained that members of the security staff who had come to the scene had not been able to help. “The initial first-response team was one guard with a baton,” said one woman who described the events on camera. “Even after the guard came, they were focusing more on clearing the crowds than saving the man.” Amitabh Agnihotri, the director of the zoo, said that tranquilizer guns were stored at the zoo hospital, roughly 350 feet from the tiger’s cage. “We do have tranquilizer guns, but by the time we could organize them, he was dead,” he said. Mr. Khan had stepped over a low outer fence to get closer to the tiger. Witnesses said they believed that he had slipped, but zoo officials said he had jumped into the moat, which is about 18 feet deep. In a written statement, Mr. Agnihotri said Mr. Khan had actually “crossed the standoff barrier of the white tiger enclosure” and had “jumped into the enclosure,” rather than fallen.