India's financial crimes agency arrested the chief minister of resource-rich eastern Jharkhand state late on Wednesday as part of an investigation into money laundering and alleged land fraud, local media reported.
The Directorate of Enforcement (ED) seized cash, a car and "incriminating documents" from Hemant Soren's home, according to the media reports.
Soren resigned on Wednesday shortly before his arrest, his party the Jharkhand Mukti Morcha (JMM) said, adding that he had not committed any wrongdoing.
In a post on social media platform X, Soren said he did not own the seized vehicle or "any illicit cash", adding that he would launch an investigation into the ED.
"I will not give up in vain, I will not accept defeat," he said late on Wednesday.
Soren will be replaced as chief minister by JMM Vice President Champai Soren, who was also a cabinet minister in the state, party spokesperson Supriyo Bhattacharya said. Both men are not related.
Jharkhand is among Indian states not controlled by Prime Minister Narendra Modi's ruling Bharatiya Janata Party.
Several tribal groups called for statewide demonstrations to protest Soren's arrest. JMM supporters held a protest in the state capital Ranchi and chanted slogans against the BJP and the financial crimes agency.