New Delhi: Prime Minister Manmohan Singh today underwent a surgery of the prostate gland at the All India Institute of Medical Sciences (AIIMS) here and he is doing fine.

"There is nothing to worry. His health is fine," PM's Media Adviser Sanjaya Baru told reporters.

The prostate enlargement is "non-cancerous", AIIMS sources said, adding "it is age related enlargement of the prostate. It is benign prostate and the operation was done through endoscopy".

Singh, 75, was admitted to AIIMS at 6 am and the surgery lasted till 9 am. "The procedure (Trans Urethral Resection of the Prostate gland) was performed to treat benign prostatic hypertrophy of the prostate (benign enlargement of the prostate gland)," Baru said. "The Prime Minister is convalescing after the surgery and has had a stable post operative course," he added.

Singh is back in his special ward and his family members are with him.

The Prime Minister will rest for the next two days at AIIMS and return home by Monday morning, Baru said.

The surgery was performed by a team of doctors led by Professor N P Gupta, head of the Department of Urology at the AIIMS.