Dhaka | Bangladesh Nationalist Party (BNP) acting chairman Tarique Rahman returned home to a rousing welcome on Thursday after over 17 years in self-exile, a move that is expected to energise his party workers ahead of the February 12 parliamentary elections.

Rahman, the 60-year-old son of ailing former prime minister Khaleda Zia, has emerged as a leading contender for prime ministership in the polls even as the country's Islamist party, Jamaat-e-Islami has been trying to expand its support base.

The homecoming of the BNP heir apparent comes amid a fresh wave of unrest and political instability gripping Bangladesh following the killing of prominent youth leader Sharif Osman Hadi, who was a prominent face in last year's mass protests that forced the collapse of the Sheikh Hasina government.

Rahman, accompanied by wife Zubaida and daughter Zaima, was received at the Hazrat Shahjalal International airport in Dhaka by BNP Secretary General Mirza Fakhrul Islam Alamgir and other senior party leaders amid tight security.

BNP emerged as the forerunner to capture power in the February polls as former prime minister Hasina's Awami League party has been barred from contesting the election.

Jamaat-e-Islami, the BNP's coalition partner during its 2001-2006 tenure in power, has emerged as its main rival in the upcoming polls after the interim government blocked Awami League's participation under the country's tough Anti-Terrorism Act.

After BNP announced Rahman's plan to return from London, he had said, "like any child, he longs to be near his critically ill mother at her moment of crisis."

Rahman's return to Dhaka also comes at a time Bangladesh-India relations are on a sharp downturn.

The BNP leader left the airport in a bulletproof bus. He is set to attend a mass reception with tens of thousands of his supporters waiting to greet him.

Rahman is also expected to go to see his octogenarian ailing mother and BNP chairperson Khaleda Zia, at the nearby Evercare hospital.

Before leaving the airport Rahman held a phone conversation with interim government chief Muhammad Yunus, BNP’s media cell said.

It is not immediately known what transpired in the phone conversation.

Zia, a three-time prime minister, has been undergoing treatment at the intensive care unit (ICU) at the hospital.

Around 4,000 army personnel, paramilitary Border Guard Bangladesh (BGB) and police in riot gear and plainclothes were deployed in Dhaka to ensure Rahman's security.

"We have enforced an overt and covert security vigil," a senior police official earlier said as supporters queued in long lines on both sides of the street from the airport to the reception site.

Civil aviation authorities disallowed any use of drones near the airport and the Evercare hospital and restricted photography at the reception site.

Bangladesh witnessed violent protests after the death of Hadi. His killing has also triggered some fresh strain in India-Bangladesh ties.

India on Tuesday sought a thorough probe into Hadi's death. India's call for a detailed probe into the case came as unsubstantiated allegations about an Indian hand in Hadi's death triggered anti-India sentiment in Bangladesh.

The relations between India and Bangladesh came under strain after the interim government headed by Muhammad Yunus came to power following the collapse of the Hasina government.

India has been expressing concerns over attacks on minorities, especially Hindus, in that country.