Elon Musk's X social network said on Wednesday that the restoration of its services in Brazil, where it had been shut down, was "inadvertent and temporary."
Some Brazilian users were surprised to once again have access to the platform, formerly Twitter, from their phones after a Supreme Court judge last month ordered its suspension in a bitter legal standoff with Musk.
In a statement, X said the company had switched network providers in order to continue providing services to its Latin American users, resulting in the temporary restoration.
"This change resulted in an inadvertent and temporary service restoration to Brazilian users," the statement said.
"While we expect the platform to be inaccessible again shortly, we continue efforts to work with the Brazilian government to return very soon for the people of Brazil."
Earlier, the Brazilian Association of Internet and Telecommunications Providers (ABRINT) attributed the return of X to an update of the app to Cloudflare software, which uses constantly changing IP addresses.
Brazil's shutdown of X infuriated Musk and has fueled a fierce debate on freedom of expression and the limits of social networks, both inside and outside the country.
The social media platform has more than 22 million users in Brazil.
The hashtag "Twitter is back" was one of the most used in the country on Wednesday.
- Ongoing feud -
Judge Alexandre de Moraes last month ordered X to be banned after Musk refused to remove dozens of right-wing accounts accused of spreading fake news, and then failed to name a new legal representative in the country as ordered.
He also ruled that those using "technological subterfuges" such as virtual private networks (VPNs) to access the blocked site could be fined up to $9,000.
Moraes has repeatedly clashed with the South African-born billionaire after making it his mission to crack down on disinformation.
Last week, he ordered the transfer of about $3 million from Musk's companies to pay fines incurred by X.
Moraes also froze the assets of X and Musk's satellite internet operator Starlink -- which has been operating in Brazil since 2022, especially in remote communities in the Amazon -- to ensure payment of fines imposed on the social network for flouting court orders.
Musk reacted angrily to the suspension, calling Moraes a "dictator" and repeatedly targeting the judge in posts to his 198 million followers on X.
Brazil's leftist President Luiz Inacio Lula da Silva had hailed the ban, but his far-right predecessor Jair Bolsonaro was staunchly against it and welcomed the technical tweak that brought X back online.
"I congratulate all those who have pushed to defend democracy in Brazil," he wrote on the platform.