Customers of the Binance cryptocurrency exchange said on Tuesday they were unable to deposit or withdraw sterling from the platform, days after British regulators cracked down on some of its activities in the country.

Britain's financial watchdog said last week that Binance, one of the world's biggest crypto exchanges, could not conduct any regulated activity and issued a warning to consumers about the platform.

Binance said the move would not have any impact on the services offered by its main site, Binance.com, which can still be accessed by Britain-based users despite the move by the Financial Conduct Authority (FCA).

But users said on Twitter they were unable to withdraw or deposit sterling at the exchange, both via the Faster Payments network or bank cards.

A "down for maintenance" message appeared, some said. Others complained that Binance had given no information beyond that.

Faster Payments, owned by Pay.UK, which oversees the clearing and settlement of UK automated payments and cheques, enables mobile, internet and other payments between British bank accounts.

"Pay.UK requires all direct and indirect participants to conduct appropriate due diligence on their customers. Binance has never been a direct or indirect participant of the Faster Payment System and the FCA ruling has not changed this," a Pay.UK spokesperson said.

"Any change in Binance's access to the service was made independently," he added.

Binance did not respond to a request for comment.

"I tried to withdraw Fiat (sterling currency) but it's blocked and it just says maintenance. Typically when there's maintenance Binance announce it on their socials etc.," one Twitter user told Reuters on condition of anonymity. "No explanation or anything was given. Frustrating."

Others tagged Binance Chief Executive Changpeng Zhao as they complained that the problem remained unfixed.

"@cz_binance how come you not fixing withdrawals for UK Binance users," asked Peter Englefield, a country DJ in Leeds, northern England.

Binance, which is facing increased scrutiny by regulators globally, offers services ranging from digital token trading to derivatives, as well as emerging technology such as tokenised versions of stocks.

Separately, Britain's Natwest Group has capped the daily amount customers can send to cryptocurrency exchanges, including Binance, because of concerns over investment scams and fraud, a spokesperson told Reuters on Tuesday.