Bangladesh's ruling alliance won virtually every parliamentary seat in the country's general election, according to official results released early Monday, giving Prime Minister Sheikh Hasina a third straight term despite allegations of intimidation and the opposition disputing the outcome.

The coalition led by Hasina's Awami League Party won 288 out of 300 seats (96 per cent) in Sunday's polls, Election Commission Secretary Helaluddin Ahmed said. The opposition alliance led by prominent lawyer Kamal Hossain won only seven seats.

The opposition rejected the outcome, with Hossain calling the election “farcical” and demanding a new election be held under the authority of a “nonpartisan government.”

The opposition claims Hasina's leadership has become increasingly authoritarian.

More than a dozen people were killed in election-related violence on Sunday and the campaign preceding the vote had been dogged by allegations of arrests and jailing of thousands of Hasina's opponents.

Hossain said late on Sunday that about 100 candidates from the alliance had withdrawn from their races during the day. He said the alliance would hold a meeting on Monday to decide its next course.

“We call upon the election commission to declare this election void and demand a fresh election under a nonpartisan government,” Hossain told reporters at a nationally broadcast news conference.

Calls to several Hasina aides seeking comment were not immediately returned.

Bangladesh's leading newspapers made banner headlines, some in red, while television stations aired round-the-clock analysis.

A headline in the country's leading English-language newspaper, the Daily Star, read, “Hat-trick for Hasina, BNP found missing in polling; atmosphere festive, tuned only to ruling party,” referring to the opposition Bangladesh Nationalist Party.

In an editorial, the newspaper said, “this was a one-sided election.”

“The blatant and starkest manifestation of an uneven state of affairs was the absence of polling agents of the opposition ... in most, if not almost all, of the polling centers in the country,” it said.

Hasina's main rival for decades has been former Prime Minister Khaleda Zia, the leader of the Bangladesh Nationalist Party, who a court deemed ineligible to run for office because she is in prison for corruption.

In Zia's absence, opposition parties formed a coalition led by Hossain, an 82-year-old Oxford-educated lawyer and former member of Hasina's Awami League party.

The secretary general of Zia's party, Mirza Fakhrul Islam Alamgir, won a seat in a twist victory.

Alamgir is a fierce critic of Hasina and he spearheaded the formation of the opposition alliance with Hossain at the helm. Alamgir had said on Sunday that he was rejecting any outcome, but it was unknown after his win was declared what he would do now.

In the run-up to the election, activists from both the ruling party and the opposition complained of attacks on supporters and candidates.

The Daily Star said 16 people were killed in 13 districts in election-related violence on Sunday.

The Associated Press received more than 50 calls from people across the country who identified themselves as opposition supporters complaining of intimidation and threats, and being forced to vote in front of ruling party men inside polling booths.

While rights groups have sounded the alarms about the erosion of Bangladesh's democracy, Hasina has promoted a different narrative, highlighting an ambitious economic agenda that has propelled Bangladesh past Pakistan and India by some development measures.

Voters “will give us another opportunity to serve them so that we can maintain our upward trend of development, and take Bangladesh forward as a developing country,” Hasina said after casting her ballot along with her daughter and sister in Dhaka.

Some 104 million people in the Muslim-majority country were eligible to vote, including many young, first-time voters, in Bangladesh's 11th general election since 1971.

Both sides were hoping to avoid a repeat of 2014, when Zia and the BNP boycotted and voter turnout was only 22pc. More than half of the 300 parliamentary seats were uncontested. The Awami League's landslide victory was met with violence that left at least 22 people dead.

About 600,000 security officials, including army and paramilitary forces, were deployed to contain violence. The telecommunications regulator shut down mobile internet services nationwide to prevent the organising of protests.