Former PM Tun Dr Mahathir Mohamad has been admitted to the National Heart Institute (IJN) today for treatment of chest infection, according to a statement Tuesday.

"Tun (Dr Mahathir) is expected to be kept under observation for the next few days. Tun is currently admitted in the general ward and based on the medical team's advice, visitation is strictly for close family members only," said the statement by IJN.

The last time he was admitted for chest infection at the IJN was November 16, 2013.

He was discharged a few days later after he responded well to the treatment.

Dr Mahathir, 91, will also be chairing a new political party, Parti Pribumi Bersatu Malaysia (BERSATU) along with Tan Sri Muhyiddin Yassin once it has been approved by the Registrar of Societies (RoS).

READ: Application for Tun Mahathir's new party submitted