(Reuters) -Collapsed crypto exchange FTX said on Saturday it had seen “unauthorized transactions”, with analysts saying millions of dollars worth of assets had been withdrawn from the platform.

Blockchain analytics firm Elliptic said that around $473 million worth of cryptoassets were “moved out of FTX wallets in suspicious circumstances early this morning,” but that it could not confirm that the tokens had been stolen.

FTX U.S. general counsel Ryne Miller said in a tweet shortly after 0700 GMT on Saturday that the firm had “expedited” the process of moving all digital assets to cold storage “to mitigate damage upon observing unauthorized transactions.”

Cold storage refers to crypto wallets that are not connected to the internet to guard against hackers.

Earlier on Saturday, Miller said in a tweet that he was “investigating abnormalities with wallet movements related to consolidation of FTX balances across exchanges.”

FTX did not respond to a Reuters request for comment.

Prior to Miller’s tweets, FTX officials appeared to confirm rumors of a hack on the firm’s Telegram channel, according to a CoinDesk report which said that the exchange had instructed customers to delete FTX apps and avoid its website.

“FTX has been hacked,” an account administrator in the FTX Support Telegram channel wrote in a message, according to CoinDesk.

Reuters could not immediately verify the details posted on FTX’s private Telegram channel.

FTX filed for U.S. bankruptcy protection on Friday and founder Sam Bankman-Fried resigned as chief executive.

The distressed crypto trading platform had struggled to raise billions to stave off collapse as traders withdrew $6 billion in crypto tokens from the platform in just 72 hours and rival exchange Binance abandoned a proposed rescue deal this week.

(Reporting by Akriti Sharma in Bengaluru and Elizabeth Howcroft in LondonEditing by William Mallard, Pravin Char and Frances Kerry)