New Delhi, Sep 23 (IANS): The security apparatus at the Delhi zoo came into question Tuesday after a 20-year-old man was killed by a white tiger inside its enclosure.

Though zoo officials termed it an "unfortunate incident", questions have been raised over the delay in action to rescue the man who fell into the enclosure and was killed by the tiger.

Private security guards were also present around the enclosure No.8 where the tiger attacked the man.

One of the guards, Praveen, called other staff by sending a wireless message but it was too late.

The zoo has 20 enclosures and each is looked after by three caretakers who are not professionally trained to handle the animals.

According to zoo sources, no professional training is given but the caretakers have been told verbally how to behave with the animals while giving food and doing other work.

On the fences of the enclosures, zoo officials told IANS that the fence has been designed as per the standards laid down by the Central Zoo Authority.

But people Tuesday said its height was very low, and that led the man to fall over it.

"There are three fences, which include a grill and a cemented wall with the same height. The grill is fine for children, but for the adults it is too low and one can fall into the enclosure if he looks down and loses his balance," 34-year-old visitor Zulfikar told IANS.

Besides, there are no CCTV cameras to cover the whole zoo. A few cameras are installed at the gate and outside the director's office, but there were no cameras installed at the incident spot.

Zoo sources told IANS that a proposal to put the whole campus under CCTV surveillance was sent to the Central Zoo Authority in 2008, but the Delhi zoo is still waiting for a reply.

At least 42 security personnel guard the zoo on weekdays, and 10 more are deployed on Saturdays and Sundays.