The prime minister of Bangladesh, Sheikh Hasina, has resigned and left the country, the head of the army has confirmed, amid some of the worst violence since the birth of the south Asian country more than 50 years ago.

In a briefing to reporters, Army Chief Gen Waker-Uz-Zaman announced he was assuming control at “a critical time for our country” and would establish an interim government.

“I am taking responsibility now and we will go to the president and ask to form an interim government to lead the country in the meantime.”

Hasina, 76, who has ruled Bangladesh since 2009, left by helicopter, a source close to the leader told Agence France-Presse news agency shortly after protesters had stormed her palace in the capital, Dhaka.