Home Affairs Minister Wong Kan Seng, Mar 3, said the multi-racial city-state has enjoyed harmony over the past three decades because its people were tolerant.

Chinese make up 77 percent of Singapore's population of 3.2 million, followed by Malays and Indians. More than 700,000 foreign workers also reside in the affluent city state.

"But we cannot take for granted that communal harmony will prevail indefinitely as a matter of course. We have seen in the last two to three years the eruption of communal clashes in the region," he said in a speech at a ministry workshop.

"These communal clashes in the region serve as sobering reminders of the fragility of racial and religious harmony and the importance of social cohesion," he said.

"To make Singapore safe and secure best home, we must continue to be vigilant and be prepared to take firm action against extremists whose activities threaten to plunge Singapore into racial or religious strife."

Wong did not give any examples.

However, Singapore's immediate neighbour Indonesia is currently dealing with a bloodbath on the island of Borneo in which rampaging Dayak tribesmen have killed more than 400 Madurese settlers and sent thousands fleeing.

Last year, religious extremists carried out raids on armories in Malaysia and went on a multi-million-dollar kidnapping spree on Jolo island in the southern Philippines