Two men wanted over the public assassination of a suspetced Sydney underworld figure have been arrested in Vietnam.

Lorenzo Lamalu, 24, was gunned down at a restaurant in Ho Chi Minh City on Thursday night, with CCTV showing a man open fire at Lamalu and another man on a footpath in front of horrified onlookers.

The gunman is then seen chasing Lamalu into the restaurant.

Lamalu’s associate, who was identified by local media as Sam Sauni, 27, was critically injured in the attack.

On Tuesday, Steve Tofa and Joseph Va’a were arrested in Ho Chi Minh City in connection with the alleged murder, however it is believed they have yet to be charged.

The two men are believed to be Samoan nationals, with the Department of Foreign Affairs and Trade (DFAT) confirming they are not Australian citizens.

It has been alleged the two men were arrested by local authorities while attempting to flee the country into Cambodia.

Vietnamese police released images of the suspected shooters, who were originally believed to be Australian.

7NEWS understands the pair travelled to Vietnam using fake passports and names; Lang Kenny Trong Minh Do and Justin John White.

Lamalu is believed to be the mastermind behind a Sydney criminal organisation, colloquial known as the “Coconut Cartel”, which declared war on the rival Alameddine gang earlier this year.

Investigations into the shooting are ongoing, with Australian Federal Police working with local Vietnamese authorities, who are expected to provide an update later on Tuesday.