BANGKOK (Reuters) - Twenty people who were aboard a Singapore Airlines flight that hit severe turbulence and diverted to Bangkok for an emergency landing on Tuesday remain in intensive care, a hospital official said on Thursday.

Of the 40 people on the flight still under treatment, 22 patients have spinal cord injuries and six have brain and skull injuries, Adinun Kittiratanapaibool, Director of Bangkok's Samitivej Srinakarin Hospital told reporters.

Adinun had said 41 people were still under treatment, but later said one person had been discharged.One passenger died of a suspected heart attack and dozens were injured after Singapore Airlines flight SQ321 encountered what the airline described as sudden, extreme turbulence while flying over Myanmar on Tuesday.

(Reporting by Panu Wongcha-Um, Writing by Devjyot Ghoshal; Editing by John Mair)