Prime Minister Manmohan Singh [Images] is still recovering from the prostate gland surgery he underwent on September 15.

Doctors have advised him to limit his activities for a few more days, a Prime Minister's Office spokesman said in a statement on Friday.

Consequently, the prime minister's visit to Himachal Pradesh on September 29 and Punjab the next day has been postponed.

"Therefore, the prime minister is unable to participate in the Shaheed Bhagat Singh Centenary celebrations," the spokesman said.

The prime minister had undergone the surgery -- a trans-urethral resection of the prostate gland -- to treat benign enlargement of the gland at the All India Institute of Medical Sciences in Delhi.

Additional Reportage: PTI