"All the immigration departments in airports, land ports, airlines operating flights to Bangladesh and all concerned people have been informed to take the necessary measures."


Hasina is currently on holiday in the United States but in her absence she has been away she has been charged with murder.


She has nevertheless vowed to return to Dhaka, the capital of Bangladesh, next week.


Leaders exiled


The move to exile the two leaders, who have alternated as prime ministers of the poverty-stricken country since 1990, concentrates political power in the hands of the country's military.


Since gaining independence from Pakistan in 1971, Bangladesh has twice had military rulers.


Zia-ur-Rahman, Zia's assassinated husband, ruled the country in the mid-seventies while H M Ershad, another military general, ruled the country for several years in the eighties.


Zia heads the Bangladesh National Party while Hasina is the leader of the Awami League.


Though they lead the two largest political parties, both have been blamed for holding the country hostage through their personal political ambitions and deep hatred for each other.


The military-backed caretaker government took power two months ago after violent protests over electoral reforms forced the president to postpone scheduled elections.


Since then, the caretaker government has cracked down on corruption, arresting hundreds of polticians including Zia's two sons, Tarique and Arafat Rahman.


Hasina has been charged with the murder of four political workers, a charge she has denied.


Though elections have been put on hold, the interim government enjoys broad popular support.