Bangladesh Prime Minister Sheikh Hasina resigned and fled the country on Monday after hundreds of people were killed in a crackdown on demonstrations that began as protests against job quotas and swelled into a movement demanding her ouster.

Jubilant crowds stormed unopposed into the opulent grounds of the presidential residence, carrying out looted furniture and TVs. One man balanced a red velvet, gilt-edged chair on his head. Another held an armful of vases.

Elsewhere in Dhaka, protesters climbed atop a statue of Hasina's father, state founder Sheikh Mujibur Rahman, and began chiselling away at the head with an axe.

The flight into exile ended a 15-year second stint in power for Hasina, who has ruled for 20 of the last 30 years as leader of the political movement inherited from her father, assassinated with most of his family in a 1975 coup.

Hasina had left the country for her own safety at the insistence of her family, her son Sajeeb Wazed Joy told the BBC World Service.

Hasina was "so disappointed that after all her hard work, for a minority to rise up against her," Joy said. She would not attempt to mount a political comeback, he said.

Earlier, army chief General Waker-Uz-Zaman announced Hasina's resignation in a televised address to the nation and said an interim government would be formed.

He said he had held talks with leaders of major political parties — excluding Hasina's long-ruling Awami League - and would soon meet President Mohammed Shahabuddin to discuss the way ahead.

"The country is going through a revolutionary period," said Zaman, 58, who had taken over as army chief only on June 23.

"I promise you all, we will bring justice to all the murders and injustice. We request you to have faith in the army of the country," he said. "Please don't go back to the path of violence and please return to non-violent and peaceful ways."

The military spokesperson's office said that a curfew would be in force from midnight on Monday until 6 a.m. on Tuesday, after which all schools, factories, colleges and universities would be open.

Hasina's government had imposed an indefinite curfew from Sunday evening and a three-day general holiday from Monday.

Hasina, 76, landed at a military airfield Hindon near Delhi, two Indian government officials told Reuters, adding that India's National Security Adviser Ajit Doval met her there. They did not elaborate on her stay or plans.

There was also no official comment from India, which has strong cultural and trade links with Bangladesh, on the events in Dhaka.

Hasina would leave Hindon for London at 1930 GMT, Indian broadcaster Times Now reported citing sources. Reuters could not immediately verify the information.

Bangladesh has been engulfed by violence since student protests last month against the quotas, which reserve some government jobs for families of veterans of the country's 1971 war of independence from Pakistan, seen as favoring allies of Hasina's party.

The protests escalated into a campaign demanding the overthrow of Hasina, and were met by a violent crackdown in which about 250 people have been killed and thousands injured.

The country, once one of the fastest-growing economies in the world, has been plagued lately by slow economic growth, inflation and unemployment.

Hasina's son Joy defended her record: "She has turned Bangladesh around. When she took over power it was considered a failing state. It was a poor country. Until today it was considered one of the rising tigers of Asia."

She had won a fourth straight term only in January this year in an election boycotted by the main opposition party, the Bangladesh Nationalist Party of her nemesis Begum Khaleda Zia.

Zia, 78, who has twice been prime minister, has been in jail since she was convicted in a graft case in February 2018. Her health has been deteriorating and she was moved to a hospital in 2019.

President Shahabuddin had ordered the release of Zia, French news agency AFP reported. But a BNP spokesman told Reuters she was in hospital for treatment and "will clear all charges legally and come out soon."

Hasina had ruled since winning a decades-long power struggle with Zia in 2009. The two women each inherited political movements from slain rulers — in Hasina's case, from her father Mujib; in Zia's case, from her husband Ziaur Rahman, who took power after Mujib's death and was himself assassinated in 1981.

"Hasina's resignation proves the power of the people," said Tarique Rahman, the exiled eldest son of the two Zias who now serves as acting chairman of the opposition party.

"Together, let's rebuild Bangladesh into a democratic and developed nation, where the rights and freedoms of all people are protected," he posted on X.

The United States urged the interim government formation process to be democratic and inclusive and encouraged all parties to refrain from further violence and restore peace as quickly as possible.

Sabrina Karim, associate professor of government at Cornell University who specializes in the study of political violence, said the interim government should ensure there is rule of law during the democratic transition, no revenge killing and destruction.

"There is perhaps some optimism for a democratic transition even if the military is involved in the process," Karim said, adding that Dhaka was one of the top troop contributors to UN peacekeeping operations and could not risk its reputation.

Student activists had called for a march to the capital Dhaka on Monday in defiance of a nationwide curfew to press Hasina to resign after clashes across the country on Sunday killed nearly 100 people.

On Monday, at least 56 people were killed in violence across the country, AFP reported. Reuters could not immediately verify the report.

Sunday's death toll, which included at least 13 policemen, was the highest for a single day from any protests in Bangladesh's recent history, surpassing the 67 deaths reported on July 19 when students took to the streets against the quotas.

Last month, at least 150 people were killed and thousands injured in violence touched off by student groups protesting against the job quotas.

Over the weekend, there were attacks, vandalism and arson targeting government buildings, offices of Hasina's Awami League party, police stations and houses of public representatives.

Garment factories in the country, which supply apparel to some of world's top brands, were closed indefinitely.

Critics of Hasina, along with human rights groups, have accused her government of using excessive force against protesters, a charge she and her ministers deny.

Hasina had said that "those who are carrying out violence are not students but terrorists who are out to destabilize the nation".