A poisonous cobra has vanished from an enclosure outside public view at the Bronx Zoo, and its Reptile House remained closed Sunday as a precaution while zoo workers searched for the missing reptile.

While the roughly 20-inch-long Egyptian cobra — a highly venomous species of snake — has been unaccounted for since Friday afternoon, zoo officials say they're confident it hasn't gone far and isn't in a public area. Its enclosure was in an isolation area not open to visitors.

"To understand the situation, you have to understand snakes," zoo Director Jim Breheny said in an email Sunday.

The animals seek out confined spaces, so this one has doubtless hidden in a place it feels safe, he said.

Once the snake gets hungry or thirsty enough to leave its hiding place, workers will have their best opportunity to recover it, Breheny said. In the meantime, the Reptile House remained closed indefinitely.

The missing cobra is an adolescent of its hooded species, which is believed to be the type of snake that was called an asp in antiquity. Cobra bites can be deadly if not treated properly, but the snakes aren't likely to attack people unless the reptiles feel threatened, according to a fact sheet on the San Diego Zoo's website.

Opened in 1899, the Bronx Zoo is run by the nonprofit Wildlife Conservation Society.