Democracy champion Aung San Suu Kyi looked set to make history in Myanmar elections on Sunday, but complaints of ballot-tampering cast fresh doubt on the fairness of the parliamentary vote.
Many supporters waited for hours in searing heat to glimpse the 66-year-old Nobel laureate, who is running for office for the first time in the by-elections, after being locked up by the junta for most of the past 22 years.
The 45 seats at stake are not enough to threaten the ruling party's majority, but a seat in parliament would give the National League for Democracy (NLD) leader a chance to shape legislation for the first time.
Observers believe Myanmar's new quasi-civilian government wants Suu Kyi to win a place in parliament to burnish its reform credentials and smooth the way for an easing of Western sanctions.
The polls were however marred somewhat by allegations of ballot-paper irregularities, notably that wax had been put over the check box for the NLD that could be rubbed off later to cancel the vote.
"This is happening around the country. The election commission is responsible for what is occurring," NLD spokesman Nyan Win told reporters.
"I have sent a complaint letter to the union election commission. If it continues like this it can harm the prestige of the election."
In the run-up to the vote, the party decried alleged intimidation of candidates and other irregularities.
Suu Kyi said on Friday that the vote could not be considered "a genuinely free and fair election" but stopped short of announcing a boycott.
A 2010 general election, won by the military's political proxies, was plagued by complaints of cheating and the exclusion of Suu Kyi, who was released from seven straight years of house arrest shortly afterwards.
The seats being contested Sunday were made vacant by MPs who joined the government. Polling was to close at 0930 GMT and official results are expected within a week, although the parties may declare how they fared earlier.
In rural villages dotted between parched fields, people stood in front of their thatched bamboo homes and waved enthusiastically as Suu Kyi's convoy snaked past on Sunday, whipping up thick clouds of dust.
A crowd of supporters and journalists mobbed the activist as she visited a polling station in the rural constituency of Kawhmu, where her main rival is a former military doctor with the ruling Union Solidarity and Development Party.
Voters, many in traditional ethnic Karen dress, queued patiently in the heat to cast their votes.
"I'll vote for Mother Suu because I love and cherish her," said 43-year-old labourer San San Win.
"We don't expect anything from her. We're really glad she came to our village," she added.
The NLD swept to a landslide election victory in 1990, but the generals who ruled the country formerly known as Burma for decades until last year never recognised the result.
Suu Kyi, who won the Nobel Peace Prize the following year, was not a candidate herself then because she was under house arrest.
A gruelling schedule of rallies and speeches has taken its toll on the health of the opposition leader, who cancelled campaigning in the week before the vote after she fell ill and was put on a drip during a visit to the south.
Suu Kyi appeared to have recovered her strength on Sunday, smiling broadly when she emerged from the house where she was staying just after dawn in Kawhmu, about two hours' drive from Yangon.
Nyan Win, the NLD spokesman, said on Saturday that Suu Kyi was "weak, but we do not need to worry".
After almost half a century of military rule, the junta in March last year handed power to a new government led by President Thein Sein, one of a clutch of former generals who shed their uniforms to contest the 2010 election.
Since then, the regime has surprised even its critics with a string of reforms such as releasing hundreds of political prisoners and welcoming the NLD back into mainstream politics.
But the continued existence of political detainees, ongoing fighting between government troops and ethnic rebels, and alleged human rights abuses remain major concerns for Western nations which have imposed sanctions on the regime.
Unlike in 2010, the government allowed foreign observers and journalists to witness Sunday's polls. More than six million people were eligible to vote.
"This is a crucial moment in Myanmar's history," UN human rights envoy Tomas Ojea Quintana said in a statement, calling the 2010 election a "missed opportunity" that should be rectified now.