Former Prime Minister Dr Manmohan Singh has been admitted to Delhi's All India Institute of Medical Science (AIIMS) after he complained of chest pain. 

The 87-year-old Congress leader was taken to the cardio-thoracic ward of the hospital at 8.45 pm and is under observation by doctors. He has been kept under the supervision of  Dr Nitish Nayak. Singh is kept under observation at the Intensive Care Unit (ICU).

Dr Manmohan Singh
Dr Manmohan SinghFacebook

'All his parameters are fine. He is under observation at the AIIMS'

"All his parameters are fine. He is under observation at the AIIMS," a source close to him said, adding that he was taken to the hospital after he felt "uneasiness". He was admitted under Dr Nitish Naik, a professor of cardiology at the All India Institute of Medical Sciences (AIIMS), around 8:45 pm.

Singh is a senior leader of the opposition Congress and is currently a Member of Parliament in the Rajya Sabha from Rajasthan. He was the prime minister between 2004 and 2014.

Rajasthan chief minister Ashok Gehlot expressed concern over the health of Singh. "Much worried to know former PM Dr Manmohan Singh ji has been admitted to AIIMS. I wish him a speedy recovery and pray for his good health and long life," Gehlot tweeted.

The veteran leader is currently representing Rajasthan in the Rajya Sabha. In 2009, Singh underwent a successful coronary by-pass surgery at AIIMS, a complex beating-heart operation that took nearly 14 hours. He also has a history of diabetes. 

In May 2008, he had undergone a cataract operation, and in September 2007, he had prostate surgery. He also underwent a bypass in the United Kingdom in 1991.