Brazilian lorry drivers who support outgoing President Jair Bolsonaro have blocked roads across the country, after his poll defeat to leftist rival Lula.
Blockages were reported in all but two states, causing considerable disruption and affecting food supply chains.
With all the votes counted, Lula had 50.9% of the valid votes against Mr Bolsonaro's 49.1% in Sunday's run-off.
The incumbent far-right president has neither conceded defeat nor challenged the results that divided the nation.
There are concerns that the outgoing president could complicate the two-month transition period before Lula (full name Luíz Inácio Lula da Silva), a former president, is due to be sworn in on 1 January 2023.
Pro-Bolsonaro lorry drivers started setting up roadblocks across the vast country soon after the election results were announced.
By Monday night, the federal highway police reported 342 such incidents, with the biggest protests going on in the country's south. Some of the blockages were later cleared by police.
Many lorry drivers have benefited from lower diesel costs during the Bolsonaro administration.
Supreme Court judge Alexandre de Moraes on Monday ordered the police to disperse the roadblocks immediately.
He warned that all those still blocking the roads on Tuesday would be each fined 100,000 Brazilian reals (£16,700: $19,300) per hour.
After narrowly losing to his arch rival. Mr Bolsonaro, 67, is said to have retired to his room to sleep.
The following morning, a presidential adviser and Mr Bolsonaro's vice-presidential running mate were seen arriving at the presidential palace in Brasilia, but it is not clear if he met people close to him and what was said.
Later, Mr Bolsonaro was seen leaving the palace and travelling to the building where his official office is located.
Combative statements from the president in the past - such as that "only God" could remove him from office - mean there is a tense wait for him to appear in public. Before the election, he had repeatedly cast unfounded doubts on the voting system.
In his victory speech soon after the results were made public, Lula, 77, touched on the political rift running through Brazil which further deepened during a bitterly fought and often acrimonious election campaign.
"This country needs peace and unity. This population doesn't want to fight anymore," he said, promising to govern for all Brazilians and not just for those who had voted for him.
Congratulations have poured in from across the world, including from the leaders of the UK, China, France, India and Russia. US President Biden said the win came "following free, fair and credible elections".
It is a stunning comeback for Lula, a politician who could not run in the last presidential election in 2018 because he was in jail and banned from standing for office.