About 30 residents were evacuated from the apartment block and firefighters were searching the building for the missing snake Thursday morning.
Officials said the cobra is believed to be somewhere in the cellar of the building, but people walking nearby are being warned to avoid the high grass as a precaution.
A local hospital is keeping the antivenom for the cobra's bite on hand in case of an attack, officials said.
The cobra escaped from the home of a man who was found to be keeping about 20 other snakes in his apartment. The reptiles were seized from his residence.