Former Bangladesh Prime Minister Sheikh Hasina, released from jail on parole, left Dhaka on Thursday for the United States for medical treatment.
She boarded a British Airways flight to London, en route to the United States, officials at the airport said.
Hasina has been suffering from high blood pressure, eye problems and hearing impairment caused by grenade blasts at a rally she addressed in Dhaka in August 2004, which killed 23 people.
Bangladesh's military-backed government arrested Hasina in July last year for alleged corruption, but it granted her eight-week parole on Wednesday for treatment abroad.
Hasina's rival and fellow former prime minister, Begum Khaleda Zia, has also been in detention since last September, facing charges of corruption. But she has refused to seek treatment overseas for arthritis and a knee problem.
Hasina told leaders of her Awami League and four advisers to the interim government late on Wednesday that she would return immediately after the treatment to actively take part in politics.
She also wants to contest a parliamentary election planned for December, said Syed Ashraful Islam, general secretary of the Awami League.