Bangladesh toughened security Saturday for an election expected to see Prime Minister Sheikh Hasina win a record fourth term but dominated by opposition claims that they have been shackled by a government clampdown.
Authorities have deployed around 600,000 police, army and other security forces ahead of Sunday's vote, a senior official said, following a deadly campaign of clashes and the arrests of opposition activists.
The forces -- which also include the elite Rapid Action Battalion (RAB), navy, border and coast guards and auxiliary police units -- will guard some 40,000 election booths across the poor South Asian nation.
"We have ensured the highest level of security in Bangladesh as per the capacity of the country," Rafiqul Islam of the election commission told AFP.
"We hope there will be a peaceful atmosphere," he said.
A heavy police presence was evident on the streets of the capital Dhaka less than 24 hours ahead of the polls opening at 8:00 am (0200 GMT) on Sunday.
Clashes have gripped the Muslim majority country of 165 million in the run-up to the vote, in which the ruling Awami League and opposition Bangladesh Nationalist Party (BNP) are leading their own alliances.
Thirteen people have been killed and thousands injured in skirmishes between supporters of Hasina and activists of the BNP, whose leader Khaleda Zia is serving 17 years in prison on graft charges.
The BNP -- which boycotted the 2014 election, handing Hasina an easy victory -- says its supporters have been deliberately targeted in a bid to deter them from voting, clearing the prime minister's path for a new term.
The 71-year-old Hasina has called for voters to back her to further bolster the economy which has shown impressive growth during her decade in power. She has rejected accusations of growing authoritarianism.
The BNP -- the main player in an alliance headed by Kamal Hossain, an 82-year-old Oxford educated lawyer who drew up Bangladesh's constitution -- has accused the election commission of bias during the campaign.
The opposition says more than 14,000 of its activists have been detained since the election was announced on November 8. The BNP said over 1,100 people were rounded up on Friday alone.
The party also alleges that around 12,000 activists were injured in attacks by ruling party followers. The Awami League denies the allegation.
The United States has raised concerns about the elections while the United Nations called for greater efforts to make the vote fair.
In a statement late Friday Amnesty International demanded that the government investigate assaults on activists and probe an attack this week on 12 journalists covering the campaign.