State-run TV reported that an indefinite nighttime curfew had been imposed on Bangladesh's capital, Dhaka, ahead of the elections.
The decision came despite the boycott by a multi-party alliance headed by Sheikh Hasina, the former prime minister.
At least 45 people have been killed and hundreds injured in street protests and transport blockades, and police say they fear worse to come.
Ban Ki-moon, the UN secretary-general, noted the situation had deteriorated to the point that the US-based National Democratic Institute for International Affairs and the International Republican Institute were refusing to monitor the elections.
"The political crisis in Bangladesh has severely jeopardised the legitimacy of the electoral process," Ban said in a statement released on Thursday in Dhaka.
"The announced cancellation of numerous international observation missions is regrettable. The United Nations has had to suspend all technical support to the electoral process, including by closing its International Coordination Office for Election Observers in Dhaka," Ban said.
Technical support includes consulting and advice on publishing results as well as ballot casting and counting.
Ban urged the army, which has been called out by the government to keep the peace, to stay neutral.
|"The United Nations has had to suspend all technical support to the electoral process, including by closing its International Coordination Office for Election Observers in Dhaka" |
Ban Ki-moon, UN secretary-general
The European Commission expressed deep regret over the political crisis.
"I am deeply disappointed that it has not proven possible for the main parties to reach an agreement paving the way for democratic and credible elections," Stefan Frowein, head of the EC delegation in Dhaka, told a news conference.
Graham Elson, EC deputy chief observer, said: "The decision to suspend the EOM [election observation mission] is a logical consequence of the unfortunate circumstances which are presently governing the holding of the parliamentary elections."
Hasina and her successor Begum Khaleda Zia, the country's immediate past prime minister, have been foes since 1991 when they jointly led a people's revolt that ousted military ruler Hossain Mohammad Ershad.
Khaleda ended her five-tear term as prime minister in October and handed over the country and the running of the elections to an interim government in a constitutionally mandated move aimed at ensuring fairness and transparency.
But Hasina's Awami League and its allies have continued to accuse the interim government of bias in Khaleda's favour and on Wednesday said they would not only boycott the election but try to disrupt it with daily strikes and blockades.