Former Prime Minister Manmohan Singh was admitted to the All India Institute of Medical Sciences in Delhi on Sunday night after complaining of chest pain, Hindustan Times reported. The senior Congress leader was taken to the cardiothoracic ward of the hospital at 8.45 pm and is under observation.

The authorities at AIIMS said that Singh had developed a reaction to a new medication. “Dr. Manmohan Singh was admitted for observation and investigation after he developed a febrile reaction to a new medication,” unidentified officials told PTI. “He is being investigated to rule out other causes of fever and is being provided care as needed.”

Singh’s office confirmed that he had been admitted but underlined that he was doing fine. “He is okay,” Singh’s office said in a statement. “He was taken to the hospital as he had fever due to the side-effect of the medication given yesterday [Saturday]. He is under observation.”

Singh, who is currently a Rajya Sabha member from Rajasthan, has undergone two heart-bypass surgeries – one in 1990 and another in 2009. The former Prime Minister suffered a fall shortly before Parliament was adjourned in March because of the coronavirus outbreak, according to NDTV. At the time his doctors had advised complete bed rest.

Political leaders cutting across party lines wished Singh a speedy recovery. Delhi Chief Minister Arvind Kejriwal said he was “deeply concerned” about Singh’s health. “Hope he makes a full recovery soon,” he tweeted. “All of India is praying for our former Prime Minister.”

Senior Congress leader Shashi Tharoor also wished Singh a complete recovery. “Concerned by reports that former Prime Minister Manmohan Singh was admitted to AIIMS in Delhi, but relieved he is not in the ICU and is in good hands,” he tweeted. “Wishing him a speedy and complete recovery.”

National Conference leader Omar Abdullah also expressed concern and said Singh’s “wise counsel and guidance are much needed during this time of crisis”.