New Delhi, Feb 22 : A month after undergoing coronary heart surgery, Prime Minister Dr. Manmohan Singh is now fit to resume his duties, doctors attending on him said.

"The Prime Minister''s four weeks recovery time is over. Four weeks mean there is good amount of healing. He is now more or less independent and can resume work," Dr Vijay D''silva, ICU specialist attending Dr. Singh said.

Dr. Singh was admitted in the All India Institute of Medical Sciences (AIIMS) on January 24, where an angiography-X-ray examination of the blood vessels was conducted on him.

He also underwent several blood chemistry tests, CT scan and ECG, which affirmed five arterial blockages in the heart.

Dr. Singh opted for immediate surgery, as he wanted to be ready and fully active before the elections. The operation lasted for over 12 hours.

Shortly after getting discharged from the hospital on February 1, Dr. Singh started performing some of his duties from his residence.

As per the advice by specialists, Dr. Singh''s diet has been supplemented with a high intake of carbohydrates and protein.

He has also been advised to follow a strict exercise regimen to keep control of his diabetes. (ANI)