Former prime minister Manmohan Singh’s condition is stable and he is under observation at Delhi’s All India Institute of Medical Sciences (AIIMS), sources in the hospital said on Monday.

The 87-year-old Congress leader was taken to AIIMS on Sunday night.

“Dr Manmohan Singh was admitted for observation and investigation after he developed a febrile reaction to a new medication,” a source said.

“He is being investigated to rule out other causes of fever and is being provided with care as needed. He is stable and under the care of a team of doctors at the cardiothoracic centre of AIIMS,” the source added.

Several political leaders, including Congress president Sonia Gandhi and Rahul Gandhi, enquired about Manmohan Singh’s health and wished him a speedy recovery.

Rajasthan chief minister Ashok Gehlot also tweeted about his health.

“Much worried to know former PM Dr Manmohan Singh ji has been admitted to AIIMS. I wish him speedy recovery and pray for his good health and long life,” Gehlot tweeted.

Delhi chief minister Arvind Kejriwal also expressed his concern about Singh’s health.

“Hope he makes a full recovery soon. All of India is praying for our former PM,” said Kejriwal.