Brazil's ex-president Jair Bolsonaro has been hospitalized in the United States after thousands of supporters rioted in his home country, according to his wife.

Her husband is "under observation in the hospital due to abdominal discomfort resulting from the knife attack in 2018," Bolsonaro's wife Michelle wrote on Instagram on Monday.

However, Michelle Bolsonaro did not provide any information about her husband's whereabouts.

The Brazilian daily “O Globo” had previously reported that Bolsonaro had been admitted to Advent Health Celebration Hospital near Orlando, Florida, because of “severe abdominal pain”.

At an election campaign event in September 2018, a mentally disturbed man stabbed Bolsonaro and inflicted serious abdominal injuries on him.

The ex-military then continued the election campaign from the hospital.

The following month he was elected President.

Bolsonaro has been hospitalized since then, including after taking office in early 2019, and has had to undergo multiple surgeries.

The 67-year-old left Brazil for the United States two days before the end of his term in office, refusing the traditional handover of the presidential sash to his successor, the left-leaning Luiz Inácio Lula da Silva, at his inauguration on January 1.

Since then he is said to have lived in the house of a Brazilian ex-martial artist in Orlando.

Radical Bolsonaro supporters stormed the government district in the Brazilian capital Brasília on Sunday.

They briefly took control of the country's most important branches of government, penetrating Congress, the Supreme Court and the government seat, Palácio do Planalto.

There they rioted, leaving a trail of destruction in their wake.

It took hours for the security forces to bring the situation back under control.

There is no extradition request

Meanwhile, the US government announced that it had not yet received an extradition request against the former head of state.

"We have not yet received an official request from the Brazilian government regarding Bolsonaro," National Security Advisor Jake Sullivan said Monday during a visit by US President Joe Biden to Mexico City.

"If such a request is made, we will take it seriously."

"As far as I know, we are not in direct contact with Bolsonaro," Sullivan said.

"So I can't say anything specific about his whereabouts." The US State Department declined to comment on Bolsonaro's residency status in the US on Monday.

Department spokesman Ned Price said in Washington that he could not provide information on an individual's visa status because it was confidential.

Head of state Luiz Inácio Lula da Silva accused his predecessor Bolsonaro of inciting his supporters.

The former president denied the allegations and condemned the attack on Twitter.