Police in Brazil have arrested five people suspected of planning to kill Luiz Inácio Lula da Silva shortly before he was sworn in as president.

Four of those detained on Tuesday are soldiers and one is a police officer, local media reported.

The five were allegedly part of a plot to kill President-elect Lula and his vice-presidential running mate, Geraldo Alckmin, on 15 December 2022, just over two weeks before the presidential inauguration.

Lula was elected in October 2022, narrowly defeating incumbent Jair Bolsonaro, who never publicly accepted defeat.

A week after Lula was sworn in, Bolsonaro supporters stormed Congress, the Supreme Court and the presidential palace and vandalised the buildings.

Police eventually cleared the buildings of the rioters and detained thousands.

Investigations into the events of 8 January 2023 as well as previous alleged attempts to prevent Lula from being sworn in have been under way since.

However, this is the first time that police have revealed an alleged attempt to assassinate Lula.

Speaking after news of the arrests broke, Social Communications Minister Paulo Pimenta said that the alleged plot to assassinate Lula and Alckmin had almost gone ahead.

"It was just details which stopped it [from being carried out]," the minister said.

Brazilian news site G1 said that what was particularly worrying was that four of those arrested were active members of the military and the fifth a serving member of the police force.

AFP news agency quoted a federal police source as saying that the four soldiers "were arrested in Rio, where they were participating in the security operation for the G20 leaders' meeting" currently under way in the Brazilian city.

According to G1, the four soldiers, who had had special forces training, are accused of forming part of a criminal organisation plotting against Lula.

Brazil's federal police said in a statement that its investigations "indicate that the criminal organisation used a high level of technical-military knowledge to plan, coordinate and execute illicit actions in the months of November and December 2022".

According to the statement, the plotters had not just planned to assassinate the president-elect and the vice-president-elect but also wanted to arrest and execute a member of the Supreme Court once their coup was successful.

Police said the plotters had nicknamed the operation "green and yellow dagger", in reference to the colours of the Brazilian flag.

According to the federal police, the plotters had debated how to best "neutralise" Lula and Geraldo Alckmin and had allegedly settled on poisoning the president-elect.

The arrests were carried out in the early hours of Tuesday morning local time and were authorised by Supreme Court Justice Alexandre de Moraes.