Saudi Arabia’s King Salman has been admitted to the hospital over an inflamed gallbladder, the royal court said Monday, further fueling speculation about the aging monarch’s health. 

King Faisal Specialist Hospital in Riyadh administered "some medical tests due to cholecystitis,” read a statement carried by the Saudi Press Agency. No further information about the 84-year-old king's condition was given. 

Salman, the custodian of Islam's holiest sites, has ruled Saudi Arabia since January 2015 following the death of his half-brother, King Abdullah. With the king’s health said to be in decline, his son, Crown Prince Mohammed bin Salman, has taken on an increasingly greater role in day-to-day affairs. 

Often called MBS, the 34-year-old heir to the throne and de facto ruler has sought to portray himself on the world stage as a modernizer. While MBS has granted women more rights and introduced various reforms, his ruthless and continued crackdown on critics, including an unprecedented purge of Saudi elites and arrests of female activists, has undercut the reputation he so carefully cultivated.