Dev Anand and Amitabh Bachchan have wished a speedy recovery to southern megastar Rajnikanth, who is admitted to the Intensive Care Unit (ICU) of a Chennai hospital.

"I pray for my dear Rajani's sound health and speedy recovery (sic), " Dev Anand, 87, posted on his Twitter page.

Amitabh, who is a close friend to Rajnikanth, also took to the micro-blogging site to share an update on the latter's health, and wished him well.

"All lovers of Rajnikant it has been disturbing to learn of his hospitalisation... I have spoken to him and been in touch with wife. Rajnikant is improving gradually she informs me, today by sms... we hope and pray that he recovers as soon as possible... our prayers, " posted the Big B.

Meanwhile, Rajnikanth is responding well to treatment, his doctors said Thursday morning.

The 60-year-old was admitted to the hospital for recurrent respiratory infection and gastro-intestinal problems May 13.

Hospital officials refused to divulge any more information citing "patient's privacy".

The actor was Wednesday shifted to the ICU to improve his breathing pattern. A multi-disciplinary team is closely watching his vital parameters to assess benefits from the multi-pronged treatment strategies.

This is the third time in over three weeks that the matinee idol has been admitted to a hospital.

He was admitted to Chennai's St. Isabel Hospital April 29 after a bout of vomiting and was discharged in the evening. He revisited the hospital May 5, after which he was again admitted to the ICU after allergic bronchitis and fever.