Jubilant Zimbabweans celebrated late into the night on Tuesday after Robert Mugabe resigned as president, BBC reported.

He held power for 37 years and once said "only God" could remove him.

While still considered by some to be an African independence hero, his many critics see him as a despot who ruled by fear and brought a once-promising economy to near ruin.

His shock resignation came in the form of a letter read out by the speaker of parliament.

In it, Mr Mugabe - who had so far resisted pressure from the public, the army and his own party to step aside - said he was resigning to allow a smooth and peaceful transfer of power, and that his decision was voluntary.

The announcement abruptly halted an impeachment hearing that had begun against him on Tuesday.

'I'm so happy'

Lawmakers from the ruling party and opposition roared with glee, and spontaneous scenes of joy erupted in the streets with people dancing, singing, honking car horns and waving flags.

"I'm so happy, wonderful, feeling so much excited, this is the greatest moment for our country," Julian Mtukudzi told the AFP news agency.

"We have been having sleepless nights hoping and waiting and we are so happy. It's over and it's done."

Activist and political candidate Vimbaishe Musvaburi broke down in tears of joy speaking to the BBC.

"We are tired of this man, we are so glad he's gone. We don't want him anymore and yes, today, it's victory," she said.

Zimbabwe's next president

The ruling Zanu-PF party says former Vice-President Emmerson Mnangagwa will succeed Mr Mugabe.

Mr Mnangagwa's sacking earlier this month triggered a political crisis.

It had been seen by many as an attempt to clear the way for Grace Mugabe to succeed her husband as leader and riled the military leadership, who stepped in and put Mr Mugabe under house arrest.

Mr Mugabe, 93, was until his resignation the world's oldest leader.

According to the constitution his successor should be the current Vice-President, Phelekezela Mphoko, a supporter of Grace Mugabe.

But Zanu-PF legal secretary Patrick Chinamasa told Reuters news agency that Mr Mnangagwa would be sworn in on Wednesday or Thursday.

Notes of caution

Despite welcoming the news, Zimbabwean opposition and civil society figures have warned that the political culture needs to change.

Opposition leader Morgan Tsvangirai told the BBC he hoped that Zimbabwe was on a "new trajectory" that would include free and fair elections.

He said Mr Mugabe should be allowed to "go and rest for his last days".

Prominent Zimbabwean opposition politician David Coltart tweeted: "We have removed a tyrant but not yet a tyranny."

Both Robert and Grace Mugabe, 52, are believed to still be at a mansion in Harare.

Robert Mugabe - Timeline of a political life

• 1924: Born in Kutama
• 1964: Imprisoned by Rhodesian government
• 1980: Wins post-independence elections
• 1996: Marries Grace Marufu
• 2000: Loses referendum, pro-Mugabe militias invade white-owned farms and attack opposition supporters
• 2008: Comes second in first round of elections to Morgan Tsvangirai who pulls out of run-off amid nationwide attacks on his supporters
• 2009: Amid economic collapse, swears in Mr Tsvangirai as prime minister, who serves in uneasy government of national unity for four years
• 2017: Sacks long-time ally Vice-President Emmerson Mnangagwa, paving the way for his wife Grace to succeed him. Army intervenes and forces him to step down