Chief Election Commissioner Kazi Rakibuddin Ahmad said voting was being "fairly" conducted, bdnews24.com reported.
"The voter turnout will be low because some parties are not contesting," he said.
The Election Commission said Saturday that polling at nearly 150 centres has been suspended due to violence.
"It's a volatile situation. Some centres have been attacked, balloting started a little late in a few others while it was suspended at several centres," he said.
"Information on these issues will be provided in the evening," he added.
The election commissioner said all steps have been taken to ensure free and fair elections.
About the ongoing poll-related violence, he said: "We tend to forget everything after the elections. But it won't be the same this time. Cases will be filed and I hope justice will be meted out."
Voting in the arliamentary polls began at 8 a.m. Sunday amid a series of violent incidents that has killed at least eight people in various districts, including an election officer.
Explosions occurred outside two polling stations in Dhaka, injuring at least five people.
Mired in controversy, the parliamentary elections are being held in just 147 out of 300 seats in 59 out of 64 districts of the country. As many as 153 candidates have already been elected unopposed amid a boycott by the main opposition party and its allies.
Some 21 parties, including former prime minister Khaleda Zia's Bangladesh Nationalist Party, are boycotting the elections over Prime Minister Sheikh Hasina's refusal to introduce a non-party interim government to oversee the elections.