The United Nations wants to see a full investigation into the arson attack on a moving train recently that claimed four lives, including a mother and her child.

"I think it is incumbent on the authorities in Bangladesh to fully investigate the source and to bring those responsible to justice," Spokesman for the UN Secretary-General, Stéphane Dujarric, told reporters in a regular briefing in New York on December 21.

Also read: Case filed over arson attack on train that killed 4

The UN extended its condolences to all victims of the arson attack. 

Bangladesh’s foreign ministry yesterday said that in the Mohanganj Express derailment incident, the local administration, police, and fire departments responded "swiftly" to the derailment caused by the removed rail tracks.

Two suspects have been apprehended, linked to the sabotage, said the government.

Also read: ‘My sister, nephew could not get out of burning bogie’, says Tejgaon arson victim Nadira’s brother

"Investigations suggest that this act was premeditated, with meetings held to plan this deadly act. This sabotage is a direct attack on the state and its people, aiming to disrupt the upcoming election and the nation's progress," said the Ministry of Foreign Affairs.

Responding to a question, Stéphane Dujarric also said they call for "free and fair" elections in Bangladesh where people can vote without any sort of intimidation.

"Obviously, we may have things to say after the elections, but our position remains unchanged," he said.

Also read: 'Not seeking justice from anyone': Husband of woman killed in Tejgaon train fire

The Ministry of Foreign Affairs has said the government and people of Bangladesh "stand firmly" against terrorism and acts of violence as the election draws near.

"They are determined to uphold peace and continue the country's socio-economic development, despite these challenges," said the MoFA on Thursday.

Meanwhile, MoFA Spokesperson Seheli Sabrin in a weekly briefing on Thursday afternoon said nine countries have confirmed to observe the 12th national parliamentary election scheduled for January 7.

India, Japan, Sri Lanka, China, Russia, Japan, Uzbekistan, Mauritius, Georgia and Palestine are sending observers, she said.

OIC, Commonwealth and Arab Parliament will also observe the elections, she mentioned.

A four-member EU expert panel is already in Dhaka to observe the election.

Also read: Tejgaon train arson a plot to crack down on opposition: Ganatantra Mancha

A diplomatic source told UNB that NDI-IRI small team will also observe the polls.

After failing to gain popular and political support, a faction of the Bangladesh Nationalist Party (BNP) and their allies have intensified their efforts to enforce a blockade, aiming to create significant impediments to the upcoming election, the foreign ministry said.

This strategic move by the BNP has led to a disturbing increase in vandalism and arson attacks across the country, according to the ministry.

Their supporters have engaged in these destructive acts to instill panic and exert undue pressure on the government to concede to their controversial demands, the foreign ministry said.

Also read: Hartal enforcers behind burning train in Tejgaon: DMP chief