New Delhi, Dec. 26 -- The son of a former prime minister of Bangladesh returned home Thursday, promising to work for a safe country after more than 17 years in self-imposed exile as a frontrunner to become the nation's next leader in upcoming elections.

Tarique Rahman moved to London in 2008 for medical treatment with permission after he was tortured while in custody during a military-backed government that ruled from 2006 to 2008.

Rahman, 60, is the acting chairman of the Bangladesh Nationalist Party, one of two major political parties in the South Asian nation of more than 170 million people. His return is seen as politically significant ahead of the next election set for Feb. 12 under the current interim government.

A flight carryin...