Doctors at the Lilavati Hospital said that the singer's condition has not worsened but continues to remain critical.
“We were told by the doctors treating him that this kind of bleeding could occur when a blood vessel within the skull is broken or leaking," said a source.
"The clot is removed after opening up the skull," said Dr Vishwanathan Iyer, consultant endovascular neurosurgeon, Kohinoor Hospital.
However the hospital authorities abstained themselves from commenting further on the kind of treatment the Gazal maestro was getting.
"Singh has been operated for brain hemorrhage. He is stable. His family would not like to disclose more details," said Lilavati Hospital"s spokesperson.
Famous singers like Anoop Jalota and Ghulam Ali visited the singer at Lilavati Hospital.