Former Prime Minister Manmohan Singh, who was admitted to Delhi's All India Institute of Medical Sciences (AIIMS) after he developed a reaction to a new medication and is stable, sources said on Monday. Doctors have confirmed that Singh is in a stable condition and under the care of a team of the cardiothoracic centre of AIIMS.

Rahul Gandhi (L), President of India's main opposition Congress party talks to India's former Prime Minister Manmohan Singh (C) and his mother and leader of the party Sonia GandhiREUTERS

Manmohan Singh was brought to the AIIMS on Sunday at 8.45 pm. According to the AIIMS sources, Singh was admitted for observation, investigation after he developed a febrile reaction to the new medication.

"He is being investigated to rule out other causes of fever and is being provided care as needed. He is stable and under care of a team of doctors at AIIMS," the source said.

The senior Congress leader is under the supervision of doctor Nitish Nayak. Singh has been kept under observation at the Intensive Care Unit (ICU).

In 2009, Singh underwent successful coronary bypass surgery at the AIIMS, a complex beating-heart operation that took nearly 14 hours.

The 87-year-old leader of the opposition Congress is currently a Member of Parliament in the Rajya Sabha from Rajasthan. He was the prime minister of the UPA government between 2004 and 2014.