On Friday staff had located but had yet to recapture the king cobra which escaped through a light fitting last weekend.
ADVERTISEMENTA zoo in Sweden has been partially closed after a venomous snake escaped from its enclosure over the weekend.
Staff at Stockholm's Skansen Zoo have been searching for the elusive king cobra, named "Sir Väs" ("Sir Hiss"), for six days.
The park said on Friday that they have located the snake but had not yet recaptured him.
The animal -- now nicknamed "Houdini" after the famous escape artist -- had only arrived at the zoo a few days previously.
A video taken by a visitor showed the serpent climbing through a light fixture in its terrarium off a tree branch.
Zoo staff found the snake overnight in the reptile section's ceiling and have closed the building, using flour, sticky traps, and special cameras to try and catch him.
The zoo later assessed that there was no general risk for employees or guests and the rest of the zoo remained open.
"He won't come out, in theory, it's so cold outside that he would not survive," Skansen Aquarium director Jonas Wahlström told AFP.
Skansen zoo has been home to king cobras for nearly 15 years, but it only took a few days for the new animal to escape on Saturday after the enclosure was fitted with new energy-saving bulbs.
"He must be a smart guy," Wahlström said. "The old lamps were too hot, which kept the snakes away."
King cobras, native to South and Southeast Asia, are the world's longest venomous snake. They mainly prey on other snakes but their bites can be fatal to humans if left untreated.