The nation of 165 million saw sparse turnout on Sunday in its first fully competitive poll in a decade widely expected to be won by Prime Minister Sheikh Hasina, giving her a third straight term in office.

Mobile internet was blocked and the streets of the capital were largely deserted as many had left to vote in their home towns.

Others were seen trickling into booths, where posters bearing the ruling Awami League's "boat" symbol far outnumbered those of the opposition.

Mahbub Talukdar, one of the five election commissioners who stirred a controversy last week by saying there was no level-playing field for the parties, said he did not see any opposition agents near the Dhaka booth where he voted, suggesting they had been kept away.

"I am receiving similar complaints from across the country on phone but what can I do alone?" he said.

A spokesman for the Election Commission said it would act on any written complaints about the lack of opposition presence at polling centres.

The deadly clashes in the southeast of the Muslim-majority country broke out between workers of the Awami League and its opponents, led by the Bangladesh Nationalist Party (BNP) of former Prime Minister Khaleda Zia.

At least one of the victims was attacked by a machete-carrying group, police said.

Alleging vote manipulation, at least three candidates fighting against the Awami League withdrew from the contest in Khulna, a divisional headquarters about 300 km southwest of Dhaka.

Rasel, a 34-year-old voter in the southeastern district of Chittagong, said he saw police and some Awami League workers he knew stopping people from entering one polling centre.

"They told me that 'voting is going on nicely, you don't need to go inside'. If you try to enter, you will be in trouble'," Rasel, who declined to give his second name fearing reprisals, told Reuters.

"The ruling party people were standing outside the polling booth. One I know for sure is an Awami League person. If I forcefully tried to enter, they would have beaten me."

The Awami League said opposition supporters were wrongly accusing the party.

The BNP boycotted the last election in 2014 claiming it wouldn't be free and fair. The party has been hobbled by the absence of Khaleda, 74, who has been in jail since February on corruption charges which she says are politically motivated.

Hasina and Khaleda have alternated in power for most of the last three decades and this is the first election the BNP has contested without its leader.

Australian Associated Press