Congress leader and former Himachal Pradesh Chief Minister Virbhadra Singh died early on Thursday, ANI reported. He was 87. The state government will observe three days of mourning for him.

Singh had tested positive for Covid-19 on June 11 for the second time in two months. He was admitted to the Indira Gandhi Medical College and Hospital in Shimla.

Dr Janak Raj, the hospital’s superintendent, told the news agency that Singh’s health deteriorated two days ago and he was put on ventilator support. “He recovered from Covid-19 but had post-Covid issues like pneumonia,” Raj said. “He had diabetes and other health issues.”

Singh served as the chief minister of Himachal Pradesh six times. He was a five-time MP and also served as the president of the Himachal Pradesh Congress in 1977, 1979, 1980 and from August to December 2012, according to PTI.

Meanwhile, political leaders took to Twitter to pay their tributes to Singh.

“Shri Virbhadra Singh Ji had a long political career, with rich administrative and legislative experience,” Prime Minister Narendra Modi tweeted. “He played a pivotal role in Himachal Pradesh and served the people of the state. Saddened by his demise. Condolences to his family and supporters. Om Shanti.”

President Ram Nath Kovind also expressed his grief over Singh’s death. He added that Singh’s political career was “marked by his commitment to serve people of Himachal Pradesh”.

Congress leader Rahul Gandhi called Singh a stalwart.

Punjab Chief Minister Amarinder Singh and his Rajasthan counterpart Ashok Gehlot also posted tributes to Virbhadra Singh.

“Deeply saddened to hear of the passing away of former Himachal CM Raja Virbhadra Singh Ji,” the Punjab chief minister said. “An able administrator and a gentleman who was loved by the people, he was not just an elder brother but also a mentor to many to us. May God grant his soul eternal peace.”

Gehlot said Singh’s contribution to the Congress and in serving people would always be remembered. “My heartfelt condolences to his family members,” he added. “May they remain strong. May his soul RIP [Rest in Peace].”

“This is an irreparable loss for Himachal, which will never be compensated,” Chief Minister Jairam Thakur said. “His contribution in the development of Himachal is exemplary, which will never be forgotten.”

Chhattisgarh Health Minister TS Singh Deo said: “With the passing of Virbhadra Singh ji, Himachal Pradesh has lost one of its greatest statesmen and most loved and admired leaders. It’s an irreparable loss not just for HP [Himachal Pradesh] but also Congress and Indian politics.”

Congress National Spokesperson Pawan Khera offered his condolences to Singh’s family. “Virbhadra Singh ji will forever be remembered as the architect of Himachal Pradesh,” he added.