Bangladesh is voting in a general election, with Prime Minister Sheikh Hasina seeking her third consecutive term in office.
Security forces are on high alert, with some 600 000 security personnel deployed across the nation.
More than 100 million people are eligible to vote.
More than a dozen people have been killed in clashes between supporters of rival political parties.
Ms Hasina is expected to win, while her main rival is in jail for corruption.
Reports say high-speed mobile internet has been ordered to be shut down until after the elections, a decision made to prevent rumours and propaganda from triggering unrest.
Bangladesh is a Muslim-majority nation of more than 160 million people and faces issues ranging from possibly devastating climate change to endemic poverty and corruption.
Since an Islamic State-claimed attack on an upscale bakery in the capital Dhaka in July 2016, the government has responded with an iron fist to put down Islamist militancy.
The country has recently been in the international spotlight as hundreds of thousands of Rohingya Muslims have fled there from neighbouring Myanmar.
The government has been praised internationally for taking them in but faces sharp criticism for its human rights record in other areas.
The polls also come months after tens of thousands young people took to the streets in large numbers to protest about road deaths – in a rare show of fury that the authorities and pro-government groups put down with force.
“All we want is corruption to be gone and driving licences to stop being handed out like candy,” one 17-year-old told the BBC in August.
The lead-up to the election has been marked by violence and a crackdown on dissent by a government that critics say has only grown more authoritarian during its 10 years in power.