DHAKA (Reuters) - Bangladesh Prime Minister Sheikh Hasina on Monday rejected opposition complaints of vote rigging and said people had gone to the polls enthusiastically in a general election that her ruling alliance swept with a landslide.

The victory consolidates Hasina’s decade-long rule in the South Asian nation, in which her government has overseen booming economic growth, but is accused of human rights abuses and suppressing dissent - charges her government denies.

In a victory speech at her official residence in the capital Dhaka, Hasina, 71, touted robust support for her Awami League-led alliance, which won 287 of the 298 seats, while the opposition Bangladesh Nationalist Party (BNP)-led alliance got six seats.

“They voted so enthusiastically,” Hasina told a room full of journalists and foreign election observers. “What do people want? They want to fulfill their basic needs. When they feel that yes, only this government can ensure it, then definitely they will vote for us.”

The opposition rejected the result and called for a fresh vote, complaining of what it said was widespread rigging.

Neighbors India and China congratulated Hasina, and a visiting election monitoring group from South Asian countries said they had found nothing amiss in voting in the capital Dhaka.

There was no immediate statement from the European Union or the United States, which had expressed concern last week over campaign violence it said had mostly impacted opposition candidates, and a delay in visas for many U.S.-funded observers who couldn’t make it into the country.

At least 17 people were killed during Sunday’s poll that followed a violent election campaign in which both sides blamed the other for casualties.

Candidates reported witnessing ballot-stuffing and vote-rigging by ruling party activists, who also barred opposition polling agents from voting centers, said opposition leader Kamal Hossain.

“We’ve had bad elections in the past but I must say that it is unprecedented how bad this particular election was,” Hossain said.

Bangladesh’s Election Commission said it was investigating allegations of vote rigging but rejected demands for another vote.

Human Rights Watch expressed concern over the election’s credibility and Amnesty International called for an impartial probe into “deeply disturbing” election violence.

“ONE-PARTY STATE”

Slideshow ( 19 images )

The opposition BNP alleged it was never granted a level playing field to campaign in the election, with thousands of its workers locked up on charges it termed as fictitious, and many candidates attacked by ruling party activists, crippling its campaign. The BNP had boycotted the last polls in 2014, not trusting Hasina to hold them fairly, and some BNP leaders said Sunday’s vote had proved them right.

The BNP went to the vote for the first time without its leader Khaleda Zia – Hasina’s arch rival and a former prime minister – who was jailed in February on corruption charges she says were politically motivated. The rivalry between the two women has largely defined Bangladeshi politics for decades.

Hasina on Sunday referred to the BNP as “terrorists”, saying the election had been “very peaceful” barring a few incidents in which workers for her party were killed.

Slideshow ( 19 images )

She said the Election Commission was independent and would investigate any allegations of rigging.

Hasina, the longest-serving leader in the history of the Muslim-majority country of 165 million people, promised more development and an improved economy in her third straight term.

Her adviser H.T. Imam said the government would consider raising the minimum wage for workers in its garment industry, which generates about 83 percent of exports and is the world’s second-largest only after China’s.

“Certainly, the Awami League enjoys strong constituencies and has support and it can get votes, but for any party to win more than 90 percent of the seats is simply too suspicious,” said Michael Kugelman, South Asia senior associate at the Washington-based Wilson Center think-tank.

“I fear that this election result signifies that Bangladesh has really become something very closely approximating a one-party state.”