The Southeast Asian nation has a long history of military rule, but the generals took a back seat for a decade of civilian-led reforms.

That ended in a 2021 military coup when democratic figurehead Aung San Suu Kyi was detained, civil war broke out, and the country descended into humanitarian crisis.

The election's third and final phase opened in dozens of constituencies across the country at 6:00 am on Sunday (2330 GMT Saturday), just a week shy of the coup's five-year anniversary.

The military pledges the election will return power to the people but with Suu Kyi sidelined and her hugely popular party dissolved, democracy advocates say the ballot is stacked with military allies.

Junta chief Min Aung Hlaing -- who has not ruled out serving as president after the poll -- toured voting stations in Mandalay, wearing civilian dress.

"This is the path chosen by the people," he told reporters in response to a question from AFP. "The people from Myanmar can support whoever they want to support."

Voting is not being held in rebel-held parts of the country, and in junta-controlled areas rights monitors say the run-up has been characterised by coercion and the crushing of dissent.

Teacher Zaw Ko Ko Myint cast his vote at a Mandalay high school around dawn.

"Although I do not expect much, we want to see a better country," the 53-year-old told AFP. "I feel relieved after voting, as if I fulfilled my duty."

- 'Fabricated vote' -

The Union Solidarity and Development Party (USDP) -- packed with retired officers and described by analysts as a military puppet -- won more than 85 percent of elected lower house seats and two-thirds of those in the upper house in the poll's first two phases.

"The junta has orchestrated the election specifically to ensure a landslide by its political proxy," UN rights expert Tom Andrews said in a statement Friday.

"States that endorse the results of these polls will be complicit in the junta's attempt to legitimise military rule through a fabricated vote."

Official results are expected late this week, but the USDP could claim victory in the hours after polling closes.

A military-drafted constitution also gives the armed forces a quarter of the seats in both houses of parliament, which will vote as a whole to pick the president.

"I don't expect anything from this election," a 34-year-old Yangon resident told AFP earlier, requesting anonymity for security reasons. "Things will just keep dragging on."

Suu Kyi's National League for Democracy party thrashed the USDP in the last elections in 2020, before the military seized power on February 1, 2021, making unfounded allegations of widespread vote-rigging.

The 80-year-old Nobel Peace Prize laureate remains detained incommunicado at an unknown location on charges rights monitors dismiss as politically motivated.

- 'Not safe at all' -

The military has long presented itself as the only force guarding restive Myanmar from rupture and ruin.

But its putsch tipped the country into full-blown civil war, with pro-democracy guerrillas fighting the junta alongside a kaleidoscope of ethnic minority armies which have long held sway in the fringes.

Air strikes are frequent in some regions, others enjoy relative peace, while some zones are blockaded, haunted by the spectre of starvation.

Polling was called off in one in five lower house constituencies, but some frontline locations went to the polls Sunday.

"Candidates still haven't held any campaigning because of security," complained one parliamentary candidate, speaking on condition of anonymity for security reasons. "It's not safe at all to travel."

There is no official death toll for Myanmar's civil war.

But monitoring group ACLED, which tallies media reports of violence, estimates more than 90,000 have been killed on all sides.

Meanwhile, more than 400 people have been pursued for prosecution under stark new junta-tailored legislation forbidding "disruption" of the election.

It punishes protest or criticism with up to a decade in prison, and arrests have been made for as little as posting a "heart" emoji on Facebook posts criticising the polls.

Turnout in the first and second phases of the vote was just over 50 percent, official figures say, compared to roughly 70 percent in 2020.