Ontology has temporarily stopped mainnet block production after a potential security concern emerged during a routine security check, suspending on-chain transactions while developers and validators investigate. The team described the halt as a preventative measure rather than a response to an active attack. No security breach or loss of user assets has been detected so far, and Ontology said its current assessment found ONT, ONG and other on-chain assets unaffected. The technical nature of the concern and the component that triggered the review have not been disclosed. No timetable was given for restarting the network, and transactions will remain unprocessed until the security review is complete. Ontology said block production will resume after the review and any necessary upgrades, while advising users to avoid time-sensitive transactions and refrain from transactions involving ONT, ONG or other on-chain assets. The network did not say whether ONT or ONG deposits and withdrawals would be restricted during the review.