Bangladesh was experiencing a "student-led revolution" after the ouster of premier Sheikh Hasina, the South Asian country's new interim leader Muhammad Yunus said.

"This is a revolution, a student-led revolution," the Nobel laureate told a news briefing.

"There's no doubt about (that) because the business of the whole government collapsed."

Yunus arrived back in Bangladesh from Europe on Thursday after he was called by the student leaders of the protests that toppled Hasina and asked to steer democratic reforms.

"I said, 'I respect you, I admire you. What you have done is absolutely unparalleled'," he said.

"'Because you ordered me to do this, I take your order'," Yunus said he told them.

Several top allies of Hasina, whose iron-fisted tenure ended with her abrupt resignation and flight to India a week ago, subsequently stepped down.

Among them were the former chief justice of the Supreme Court and the central bank governor.

They had been issued ultimatums to quit their posts by students.

Yunus said their resignations had been conducted legally.

"I'm sure they will find the legal way to justify all of this, because legally... all the steps were followed," he said.

Yunus made the comments at an off-the-record media briefing on Sunday night at a state building being used as a temporary seat of government.

His office agreed to their publication on Monday evening.