SINGAPORE - Singaporeans young and old must take care of one other and not allow the generation gap to cause friction, said Prime Minister Lee Hsien Loong on Monday.

Citing a recent trend of unhappiness between the elderly and the younger generation in Japan, he said this serves as a "cautionary tale" for Singapore.

Both countries are grappling with a rapidly ageing population. One in four Japanese are aged 65 and older. In Singapore, the ratio rose from one in nine last year to one in eight this year.

In a Facebook post, Mr Lee discussed a commentary in English daily Japan Times titled "Generations square off in a battle for the ages", which illustrated the rising conflict between the young and old.

"Japan's young are unhappy they have to pay for pensions and medical care for the old, at the expense of their own financial security," said Mr Lee.

"Meanwhile, the old bristle that the young are uncaring and ungrateful."

The article included anecdotes of the elderly hogging seats on trains and cutting in line at supermarkets, he said, despite Japan's reputation for social cohesion and community mindedness.

"It is a cautionary tale for Singapore," said Mr Lee. "We must take care of each other and not let this happen here."