Fifteen Bangladeshis died and hundreds were injured as a fresh wave of political violence swept the country.
The republic is currently gripped by a three-day strike aimed at forcing the government to quit.
Four people – including a youth, a truck driver and a ruling party activist – were killed on Monday, police said.
The violence erupted on Friday.
Fakhrul Islam Alamgir, of the opposition Bangladesh Nationalist Party (BNP), said the government could not be trusted to conduct a credible election. Instead they say Prime Minister Sheikh Hasina should install a neutral caretaker administration to conduct the forthcoming general election, which must be held by January.
But Hasina rejected the idea, saying unelected people should not be allowed to supervise the vote.
Corruption-plagued Bangladesh is one of the poorest nations on Earth, but the tension is a fresh threat to the garment export industry which has already been rocked by a string of deadly factory accidents over the past year.
Hasina talked with BNP leader Khaleda Zia by phone on Saturday, but they failed to defuse the crisis. The women have alternated as prime minister for most of the last 22 years, most of the time barely speaking to each other.
Hasina has offered the formation of an all-party government to see through the elections with her staying as head of government.
Bangladesh has already been hit by a wave of violent protests over war crimes convictions and more than 100 people have been killed in protests and counter-protests this year.