Former West Bengal chief minister Buddhadeb Bhattacharya's health condition improved on Monday as doctors removed him from mechanical ventilation and put him on non-invasive support, doctors treating him said.

Bhattacharya, 79, underwent a CT scan of his thorax in the morning which showed improvement in his health, they said.

"Mr Bhattacharya's health has improved. He is conscious and responding to treatment. He is progressing well. His test reports are also satisfactory and his parameters have also improved," a doctor said.

Chief Minister Mamata Banerjee, who went to see Bhattacharya, said the latter waved his hands after seeing her.

"I found him stable as he waved his hands after seeing me. Doctors are doing their best. I would like to thank the hospital for their effort," Banerjee told reporters after coming out of the hospital.

"His blood pressure and oxygen saturation are satisfactory, but he is still not out of danger. His lungs were badly affected after he was infected by coronavirus in 2021. In the last 24 hours, his condition improved a lot. We are conducting check-ups on an hourly basis," the doctor said.

Bhattacharya, who was rushed to Woodlands Hospital here with breathlessness on Saturday, was diagnosed with lower respiratory tract infection and 'Type 2' respiratory failure. He has been suffering from COPD (chronic obstructive pulmonary disease) and other age-related ailments.

He served as the chief minister of West Bengal from 2000 to 2011, a tenure that was marked by agitations over the acquisition of land for industries led by Mamata Banerjee.

Over the last few years, Bhattacharya stayed away from public glare due to his deteriorating health and remained confined to his Palm Avenue apartment.

He was last seen in public when he surprised party workers by arriving unannounced at the Left's rally at Brigade Parade Ground in Kolkata, ahead of the 2019 Lok Sabha polls, with oxygen support.

Bhattacharya stepped down from the CPI(M)'s politburo and central committee in 2015, and gave up membership of the party's state secretariat in 2018.

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