DILI, East Timor (AP) — East Timor on Friday marked the 20th anniversary of a referendum that secured its independence from Indonesia, which invaded the former Portuguese colony in 1975.

Commemorative banners and posters filled the streets of Dili, where thousands gathered for festivities including speeches, musical performances and fireworks.

Guests included Australian Prime Minister Scott Morrison, who was also to sign a maritime boundary treaty and seabed oil and gas revenue-sharing deal that can benefit the impoverished nation of 1.3 million people.

The 1999 vote under U.N. auspices overwhelmingly favored establishing an independent state, despite widespread Indonesian intimidation and violence. Success at the polls, which were unexpectedly offered by an overconfident Indonesian government, came after a long-running and but largely fruitless resistance struggle.

Indonesia's military responded to the referendum results with a scorched earth campaign before departing. Australia spearheaded a U.N. military mission to restore order from the chaos as the Indonesian forces left.

"So now we are free from the colonizer and oppressor, but I continue to ask the government to work hard in order to accelerate national development," said government worker Aniceto Do Rosario, one of those celebrating Friday.

He said the event was important because many of his countrymen lost their lives in the resistance struggle against the Indonesians.

"It is a great day for Timor-Leste," Morrison, referring to the host country by its official name, said after meeting with his East Timorese counterpart, Taur Matan Ruak. "This day 20 years ago, when more than 400,000 people cast their ballots and decided their own future, the nation was born and democracy was celebrated."

The celebration's chief organizer, Xanana Gusmao — the country's independence hero who was its first president, from 2002 to 2007, and prime minister from 2007 to 2015 — called on all citizens to reflect on the resistance struggle, highlighting the courage of those who defied violence to go to the poll two decades ago.

He said that independence was not obtained free of charge, but through a long process of struggle, and caused great human and material losses.

The young nation has had a rocky infancy, with a moribund economy reliant on a dwindling offshore oil revenues and bitter factional politics that has occasionally erupted into violence.

Little progress has been made in addressing poverty in rural areas, where nearly 70 percent of East Timorese live. The U.N. estimates nearly half the population lives below the extreme poverty line of $1.90 a day and half of the children under 5 suffer moderate to severe physical and mental stunting as a result of malnutrition.

Morrison used the occasion of his visit to unveil several aid measures for East Timor. He announced that Australia will pay for a new wharf on East Timor's north coast that will help the country operate two patrol boats Australia will hand over in 2023.

He also said Australia will help upgrade the country's internet access by paying for the engineering and design work needed to link East Timor via a fiber-optic cable to a telecommunications cable system along Australia's northwest coast.