At least 11 people have been killed in violence related to national elections in Bangladesh, with police opening fire on protesters and opposition activists and more than 100 polling stations being torched.
The polls have been boycotted by the opposition and described as flawed by the international community.
Prime minister Sheikh Hasina's refusal to heed opposition demands to step down and appoint a neutral caretaker to oversee the election led to the boycott, undermining the legitimacy of the vote.
Opposition activists have staged attacks, strikes and transportation blockades amid unrest that has left at least 286 people dead since last year.
"We never expected such an election," said Aminul Islam, a resident of the capital, Dhaka, who refused to vote.
" For such a situation, both the government and opposition are responsible. They don't want to establish democracy."
Police opened fire to stop protesters from seizing a polling centre in Bangladesh's northern Rangpur district, killing two people, authorities said.
In a similar incident in neighbouring Nilphamari district, police fired into about two dozen protesters, killing two people.
Police gave no further details, but Dhaka's Daily Star newspaper said the four men who were killed belonged to the opposition Jamaat-e-Islami party.
Police said another seven people were killed in election-related violence elsewhere, including a polling official who was stabbed to death by suspected opposition activists.
Local media reported that attackers torched at least 127 school buildings across Bangladesh in overnight attacks. The buildings were to be used as polling stations.
As of Sunday afternoon, voter turnout appeared to be low. The voting began at 8am, but local television stations showed mostly empty polling stations.
"The boycott of the election by several parties may have contributed to the low turnout," Chief Election Commissioner Kazi Rakibuddin Ahmad told journalists at his Dhaka office.
The opposition boycott led to 153 of Parliament's 300 elected seats going uncontested.
The European Union, the United States and the British Commonwealth did not send observers for what they considered a flawed election. US State Department deputy spokeswoman Marie Harf said that Washington was disappointed that the major political parties had not reached a consensus on a way to hold free, fair and credible elections.
By mid-morning on Sunday, voting was suspended at least 149 polling centres because of attacks, the election commission said.
Analysts say the political chaos could exacerbate economic woes in this deeply impoverished country of 160 million and lead to radicalisation in a strategic pocket of South Asia.
Ms Hasina's refusal to quit and name an independent caretaker administration, which resulted in the boycott by opposition parties, means the election was mainly a contest between candidates from the ruling Awami League and its allies.
Awami League candidates ran unchallenged in more than half of the country's 300 parliamentary constituencies.
Bangladesh has a grim history of political violence, including the assassinations of two presidents and 19 failed coup attempts since its independence from Pakistan in 1971.
The squabbling between Ms Hasina and opposition leader Khaleda Zia has become a bitter sideshow as both women, who have dominated Bangladeshi politics for two decades, vie to lead the country.