Superintendent Pablito Cordeta, Manila Fire Department marshal, said the fire started around 3:52 p.m. at the newly refurbished session hall, located on the second floor.
Chief Justice Reynato Puno said he was in a meeting in the building when the fire began.
"I was in a meeting in the en banc conference room when I saw smoke coming out from the flooring. Immediately we went out of the room and that’s when the alarm went off," he told reporters.
Cordeta said it was fortunate that the fire occurred during office hours and not in the evening when the building was empty with no one to notice the blaze.
Puno assured that records of court cases were safe.