Binance will begin customer withdrawals in phases after a preliminary investigation into a reported $6.3 billion heist, according to the company. The move comes after the cryptocurrency exchange said attackers were able to access systems linked to withdrawals.

According to Binance’s preliminary findings, the attackers used those systems to facilitate unauthorised transfers from cryptocurrency wallets. The company has not provided further details on the scope of the breach or the assets affected.

The withdrawal process is expected to resume in stages, with Phase 1 including selected customers and services. Binance has not yet said when the next phases will begin.