Nobel Peace Prize winner Muhammad Yunus on Thursday paid tribute to those killed in Bangladesh's deadly protests that toppled Sheikh Hasina's government, saying their sacrifices had brought the nation a "second independence".

"Today is a glorious day for us," he told reporters at the airport in Dhaka shortly after returning to the country to lead a caretaker government.

"Bangladesh has created a new victory day. Bangladesh has got a second independence."

Yunus called for the restoration of order after weeks of violence that left over 455 people dead, calling on citizens to guard each other, including minorities who came under attack.

"Law and order is our first task [...] We cannot take a step forward unless we fix the law and order situation," he said.

"My call to the people is if you have trust in me, then make sure there will be no attacks against anyone, anywhere in the country."

Yunus, 84, could be sworn in as the country's new leader as soon as Thursday evening.

"Every person is our brother [...] our task is to protect them," he said, adding that "the whole of Bangladesh is one big family".

He choked with emotion as he recalled the killing of student activist Abu Sayeed, shot dead in July by police from close range.

He paid tribute to the youth who sparked the protest movement and those who risked all for their desire for change.

"They protected the nation and gave it a new life", he said. "Because of them, Bangladesh has got a second independence."