Malaysia's former leader Najib Razak was hit with a travel ban Saturday as speculation mounted he was about to flee the country following his shock election loss, in a possible bid to avoid prosecution over a multi-billion-dollar scandal.
An angry crowd had gathered at a Kuala Lumpur airport, shouting at vehicles and seeking to stop them entering, after a purported flight itinerary leaked online showed Najib and his unpopular wife were planning to head to Indonesia.
Later Saturday, Najib -- who has been under growing pressure from inside his Barisan Nasional (BN) coalition since this week's landslide loss -- announced he was quitting as head of BN as well as its main party.
The coalition's defeat in the election at the hands of an alliance led by his one-time mentor Mahathir Mohamad amounted to a political earthquake, which toppled an increasingly authoritarian regime that had ruled the country for six decades.
At 92, Mahathir is the world's oldest state leader. The former autocrat previously served as prime minister for over two decades and was a BN stalwart.
But he came out of retirement and defected to the opposition in a bid to unseat Najib over allegations that huge sums were looted from sovereign wealth fund 1MDB, which Najib set up and oversaw.
Speculation had been mounting that Najib might try to flee the country as Mahathir has pledged to investigate the controversy if he won power.
As an image of the leaked manifest for a flight to Jakarta spread like wildfire online, Najib insisted in social media posts he was planning only a "short break" overseas to rest after the election and would be back next week.
But anger quickly mounted among social media users who accused the defeated leader of seeking to flee, and the immigration department swiftly announced both he and his wife Rosmah Mansor were banned from leaving Malaysia.
Mahathir confirmed he had issued the order to stop the pair leaving.
"It is true that I prevented Najib from leaving the country... he and his wife," he told a press conference.
Najib said in a tweet: "I respect the decision and I will remain in the country with my family."
Rosmah has long been a lightning rod for public anger in Malaysia due to her reported love of luxury shopping trips and vast collection of designer handbags.
When asked if the restrictions on Najib were due to 1MDB, Mahathir said: "There are a lot of complaints against him all of which have to be investigated... we find that some of the complaints are valid.
"We have to act quickly because we don't want to be saddled with a problem of extradition (requests) from other countries."
Earlier, as dozens of people descended on the airport in a bid to stop them leaving, riot police were stationed by the gate of the airport where it was believed Najib would enter.
As a white van with heavily tinted windows attempted to pass by, the crowd surrounded the vehicle and demanded it be opened so they could see who was inside.
It was only allowed to pass after those inside rolled down a window to prove Najib was not in the van.
Later Saturday, in an emotionally charged press conference, Najib announced he was stepping down as chairman of BN and president of its main party, the United Malays National Organisation (UMNO).
His departure had seemed increasingly inevitable as rumblings of discontent grew louder following BN's historic wipeout at the polls.
"If the party failed in the general election, the leader has the moral obligation to step aside," he said.
Mahathir also announced the first three appointments to his cabinet -- Lum Guan Eng as finance minister, Muhyiddin Yassin as interior minister and Mohamad Sabu as defence minister.
The US State Department alleges in civil lawsuits that $4.5 billion was pillaged from 1MDB in an audacious scheme of fraud and money-laundering, and funnelled to the United States where it was used to buy everything from artwork to high-end real estate.
Najib and 1MDB deny any wrongdoing.
One of the biggest developments since Mahathir's shock win was his announcement Friday that the king had agreed to pardon jailed leading politician Anwar Ibrahim, his former nemesis turned ally.
This would pave the way for Anwar's return to politics and to potentially become premier later. Mahathir has said he plans to eventually hand the premiership to Anwar.