Fireworks explode during Singapore's Golden Jubilee celebrations near the central business district August 9, 2015. Singapore marks 50 years of independence on Sunday. [Photo/Agencies]

Fireworks lit up Singapore's sky as crowds celebrated the city state's 50th anniversary on Sunday, an occasion of national pride the ruling party is expected to exploit by calling an election next month.

An island of 5.5 million people that sits just north of the equator, Singapore was a post-colonial backwater when it gained independence from Malaysia in 1965. It is now a global business hub, and one of the richest countries in the world.

The highlight of the day's celebration, a nearly three-hour long parade in the evening, showcased military vehicles, performances by the island nation's different ethnic groups, and an aerial show by 50 military aircraft. A 26,000 strong audience gathered at the central stage, along with millions watching on television.

It is the second time this year that Singaporeans have come together to reflect on the national success. The first was after the death of the first prime minister, Lee Kuan Yew, in late March.

"At 50 years, as we stand at a high base camp, we look back and marvel how far we have come ... " Prime Minister Lee Hsien Loong, the son of Lee Kuan Yew, said in a televised speech on the eve of the national day.

"From this base camp, we can also look forward to new peaks ahead. The journey ahead is uncharted. But we must press on, because we aspire to do better for ourselves and our children."

He spoke at the Victoria Concert Hall, where his father launched the People's Action Party in 1954. The party has ruled Singapore since independence.

Regional leaders attending the parade included Malaysian Prime Minister Najib Razak, China's Vice President Li Yuanchao and Australian Deputy Prime Minister Warren Truss.