Singapore's Lee Kuan Yew in hospital

Lee Kuan Yew at a conference in Tokyo last year. The former Singapore prime minister is recovering in hospital after suffering from an irregular heartbeat, the government said today

Singapore's founding prime minister Lee Kuan Yew is recovering in hospital after suffering from an irregular heartbeat, the government said Saturday.

Lee, 89, will remain at Singapore General Hospital for a few days, said a statement issued by the office of his son, current Prime Minister Lee Hsien Loong, 61.

The elder Lee was confined on Friday "after experiencing a suspected transient ischaemic attack (TIA)" associated with a prolonged episode of irregular heartbeat, the statement said.

TIA occurs when blood flow to a part of the brain stops briefly, according to the statement, which added that a person who suffers from this "will have stroke-like symptoms which clear in less than 24 hours".

"He has recovered but will remain warded for a few days for the doctors to adjust his medications and for observation," the statement said.

Supporters quickly posted messages on the prime minister's Facebook page wishing his father a speedy recovery.

"Take good care of him. He is your top priority! Put aside the grouses of some Singaporeans," Margaret Khoo wrote.

Lee's hospitalisation was announced as a mass rally was being held by more than 2,000 Singaporeans demanding curbs on immigration and attacking the government over a range of issues.

Lee Kuan Yew, who retired from the cabinet in 2011 but remains a member of parliament, is widely credited with transforming Singapore from an economic backwater to one of Asia's fastest-growing economies.

He served as prime minister from 1959, when Singapore gained self-rule from colonial ruler Britain, until he stepped down in 1990 in favour of his deputy Goh Chok Tong, who in turn handed power to Lee's son in 2004.

The People's Action Party co-founded by the elder Lee has been returned to power in every election since 1959 and holds 80 of the 87 seats in parliament.

In November 2011, his physician daughter Lee Wei Ling revealed that the former leader was suffering from a neurological disease that makes it difficult for him to walk steadily.

Lee, a longtime fitness buff, has visibly slowed since his wife of 63 years Kwa Geok Choo died in 2010.