Former Bangladeshi prime minister Khaleda Zia said Islamic extremists were plotting to kill her ahead of elections on Monday.
The allegations came a day after police arrested two men linked to a banned Islamic militant group near where she had held a campaign rally.
"There is no doubt they were meant to kill me," the Bangladesh Nationalist Party (BNP) leader told supporters in her hometown of Femi on Wednesday.
"A conspiracy is on to foil the election by killing me," she said, adding "they have become desperate, seeing the mass support at BNP election rallies."
Zia and her arch rival, Awami League party leader Sheikh Hasina Wajed, were jailed by the army backed government under its crackdown on corruption. The government had tried to exile both women but failed.
They have been released to take part in the elections.
Bangladesh which has a history of political violence and assassinations has imposed a tight security clampdown ahead of the polls, deploying some 50,000 military personnel and 600,000 police officers.
The Muslim majority country has been hit by a series of attacks by Islamic militant groups in recent years including 400 blasts on just one day in August 2005 by the banned Jamayetul Mujahideen Bangladesh (JMB).
Zia, who was in power from 1991 to 1996 and from 2001 to 2006, was often accused of failing to tackle Islamic militants. She reacted in 2005 by arresting 1,000 JMB members.
The group's leaders were last year executed by the current regime.
The US Department of State has, meanwhile, issued a travel advisory for its citizens travelling to Bangladesh.
"Large gatherings in Bangladesh, including those organised for campaigning purposes, in the past have erupted in violence," the alert said. "Several newspapers also have reported terrorist threats focused on the elections."
A spokesman for the US embassy in Dhaka said it was common for the department to issue a travel alert before elections.
The British High Commission also warned its citizens the elections could spell a "turbulent period" in the country.
It said that the government may shut down the mobile phone network on election day and advised Britons in Bangladesh to keep a low profile.
"Those not at work will be best placed at home," the high commission said in an email to Britons last week.
Last week an Indian TV station reported Indian intelligence officers knew of a plot by another Islamic group, Harkat ul Jihad al Islami (HUJI), to kill Sheikh Hasina.