Former Prime Minister Manmohan Singh's health is now stable and under observation, said hospital sources in All India Institute of Medical Sciences (AIIMS). The former PM was admitted to the hospital on Sunday after he complains of chest pain.

The sourcessaid that Singh had developed a reaction to a new medication and furtherinvestigation is being carried on him to rule out other causes of fever.

Accordingto sources, Singh was admitted for observation and investigation after hedeveloped a febrile reaction to a new medication.

The hospital sources said that Singh was being investigated to rule out other causes of fever and in being provided care as needed. He is stable and under care of a team of doctors at the Cardiothoracic Centre of AIIMS.

Asource close to him said that all his parameters are fine and is now underobservation at the AIIMS.

In2009, Singh underwent a successful coronary bypass surgery at the AIIMS.

A number of leaders expressed have expressed concern over hishealth and wished him a speedy recovery.