Mahathir is expected to remain at the National Heart Institute in Kuala Lumpur “for the next few weeks for treatment and observation”, his office said in a statement.

The centenarian, widely credited for transforming Malaysia into an industrial nation during his first stint as premier from 1981 to 2003, has a history of heart problems and has been in and out of the hospital in recent years, including for bypass surgeries.

He was last admitted to the hospital for fatigue following a picnic celebration for his 100th birthday last July.

Mahathir was prime minister over two separate stints, with the first lasting 22 years. He returned as premier in 2018 after leading the opposition coalition to a historic win, but his government collapsed after less than two years due to infighting.