Former President Pranab Mukherjee's health continues to be critical and he remains on ventilator support, the Army's Research and Referral hospital said on Wednesday.
He was admitted to the hospital in Delhi cantonment on August 10 and was operated for removal of a clot in the brain.
"Shri. Pranab Mukherjee's health condition continues to remain critical. Presently he is haemodynamically stable and on a ventilator," a statement from the hospital said.
The 84-year-old's condition had worsened on Tuesday and he had not shown signs of improvement, the doctors attending on him said.
He had also tested positive for COVID-19 prior to the surgery on Monday.
Meanwhile, prayers for his speedy recovery were performed in his hometown Kiranhar in West Bengal's Birbhum district.
The residents have started a 72-hour ''yagna'' since Janmashtami on Tuesday for his recovery.
The former President's family members also offered prayers in his ancestral village Miriti, a few kilometres from Kirnahar, during the day.
Sharmishta Mukherjee, Pranab Mukherjee's daugher, posted an emotional message on Wednesday morning stating that she hopes God chooses the best path for him and gives her the strength to accept whatever comes ahead.
She also recalled that last year around the same time her father was awarded the Bharat Ratna, the highest civilian award of the country and this year, he is critically ill.
"Last year 8 August was 1 of d happiest day 4 me as my dad received Bharat Ratna. Exactly a year later on 10 Aug he fell critically ill. May God do whatever is best 4 him & give me strength 2 accept both joys & sorrows of life with equanimity. I sincerely thank all 4 their concerns" her tweet said.
(With input from agencies)