Millions voted in Burma's historic general election that will test whether the military's long-standing grip on power can be loosened. Opposition leader Aung San Suu Kyi's party is expected to secure an easy victory.

In a country that was under military rule for almost a half-century, many of the eligible 30 million voters were voting for the first time. It was the first time even for Ms Suu Kyi, the epitome of the democracy movement who defied the junta for decades.

Wearing her trademark thazin flowers in her hair, a smiling Ms Suu Kyi arrived at the polling station near her lakeside residence, where she was mobbed by hundreds of journalists. She quickly cast her vote and left without speaking to reporters.

Many people lined up in Buddhist temples, schools and government buildings early in the morning to vote, well before a heavy downpour beat down in Yangon an hour before voting ended in the late afternoon.

Election monitors called it "a remarkable day" full of excitement and energy.

"This is very, very significant ... it's the first time that most people in the country will have an opportunity to vote for the main opposition party," said Richard Horsey, a Burma analyst.

Although more than 90 parties are contesting, the main fight is between Ms Suu Kyi's National League for Democracy party, and the ruling Union Solidarity Development Party, made up largely of former junta members. A host of other parties from ethnic minorities, who form 40 per cent of the country's 52 million people, are also running.

The election, however, will not bring full democracy to this nation, which spent nearly five decades under brutal military rule and the last five years under a quasi-civilian government. Burma's constitution guarantees 25% of seats in parliament to the military, and was rewritten to keep Ms Suu Kyi, the country's most popular politician, from the presidency.

This time, however, there is hope that the election will move Burma a step closer to democracy.

After taking power in 1962, the junta first allowed elections in 1990, which Ms Suu Kyi's party won overwhelmingly. A shocked army refused to seat the winning lawmakers, with the excuse that a new constitution first had to be implemented - a task that ended up taking 18 years and intense international pressure. It finally held new elections in 2010, which the opposition boycotted, citing unfair election laws.

The USDP won by default and took office in 2011 under President Thein Sein, a former general who began political and economic reforms to end Burma's isolation and jumpstart its moribund economy. But the USDP's popularity, or lack of it, was really tested in the 2012 by-election when the National League for Democracy won 43 of the 44 seats it contested.

Ms Suu Kyi couldn't vote in any of those elections, either because she was under house arrest or there was no election in her residential area. But she did win a seat to the parliament in the by-election.

Even if her party secures the highest number of seats in the bicameral parliament in today's vote, it will start with a disadvantage because of the reserved seats for the military in the 664-seat Parliament.

This means in theory that the USDP, with the military's support, need not win an outright majority to control the legislature. To counter that scenario, the NLD would require a huge win.

That may not be farfetched, given Ms Suu Kyi's popularity.

After the polls, the newly elected members and the military appointees will propose three candidates, and elect one as the president. The other two will become vice presidents. That vote won't be held before February.

Ms Suu Kyi cannot run for president or vice president because of a constitutional amendment that bars anyone with a foreign spouse or child from holding the top jobs. Ms Suu Kyi's sons and late husband are British.

The military is also guaranteed key ministerial posts - defence, interior and border security. It is not under the government's control and could continue attacks against ethnic groups. But critics are most concerned about the military's constitutional right to retake direct control of government, as well as its direct and indirect control over the country's economy.

There are concerns also about the vote's credibility, because for the first time about 500,000 eligible voters from the country's 1.3-million-strong Rohingya Muslim minority have been barred from casting ballots. The government considers them foreigners even though many have lived in Burma for generations. Neither the NLD nor the USDP is fielding a single Muslim candidate.