Hundreds of mourners and survivors on Wednesday commemorated the 20th anniversary of the bombings that killed 202 people on the Indonesian resort island of Bali.

Eleven of the victims were from Hong Kong. Many were members of the Hong Kong Football Club's Vandals rugby team.

Grieving families, attack survivors and representatives from several embassies are attending a memorial in Bali's popular tourist hub of Kuta, where Al-Qaeda-linked militants detonated bombs at a bar and nightclub on October 12, 2002.

"It's okay that some people have forgotten what happened 20 years ago but there are still real victims, there are children who lost their parents in the bombing," 47-year-old victim Thiolina Marpaung, one of the organisers of the memorial who was left with permanent eye injuries in the attack, said.

"I don't want them to be forgotten."

Australian Prime Minister Anthony Albanese attended a service in Sydney to pay tribute to those who died, of which over 80 were Australians.

Albanese joined the relatives of the victims at the event in the beachside suburb of Coogee, from where six members of a local football club died in the blasts.

“Twenty years ago, an act of malice and calculated depravity robbed the world of 202 lives, including 88 Australians.

“Twenty years on, the ache does not dim. For most of us, what happened on that fateful night is beyond imagining. The sudden terrible light followed by the sudden terrible darkness.”

Meanwhile, the Indonesian government is considering an early release for Bali bombmaker Umar Patek. He has only served half of his 20-year sentence.

Jakarta has held off freeing him after angering Australia and victims' relatives who say his pending release has caused fresh trauma before they marked the anniversary. (Agencies)