Dhaka  - Former Bangladeshi prime minister Sheikh Hasina left Dhaka for the United States Thursday on an eight-week parole to receive medical treatment, officials said.

Hasina, who faces more than a dozen corruption charges in courts in Bangladesh, was released from jail Wednesday and took a flight to London Thursday on her way to the United States, where she was expected to undergo surgery on her ears.

Her doctors said her ears were damaged in a grenade attack by suspected Islamic militants at a rally in Dhaka nearly four years ago.

Interior Ministry officials said security was heightened at the airport as thousands of the former premier's supporters gathered to chant slogans for the opposition leader.

Hasina's departure followed more than 300 days of imprisonment in a makeshift jail in the high-security parliamentary complex in the capital.

The 63-year old who leads the Awami League, country's biggest political party, was arrested in July after she was accused of extortion and acceptance of bribes from leading businessmen.

Hasina, who was prime minister from 1996 to 2001, denied the charges, saying they were intended only to tarnish her political image.

Before leaving for abroad, Hasina called on party officials and workers to maintain unity and prepare themselves for the general election scheduled in December.

Media reports said the opposition supremo agreed to join a government opposition dialogue aimed at holding a free and credible election for returning democracy to Bangladesh.

Bangladesh is being governed by an military-backed interim administration that took over in January 2007 after widespread political unrest. (dpa)