Sparkpool, the second largest Ethereum mining pool in the world, will be closed due to China’s ongoing crackdown on cryptocurrencies.

The mining pool officially announced on September 27 that it had suspended access to new users in mainland China in response to Chinese authorities taking new measures against the use of cryptocurrencies in the country.

After the initial restrictions last Friday, Sparkpool will continue to suspend its services and plans to suspend existing mining pool users both in China and overseas on September 30th.

According to the announcement, the measures to ensure the security of users’ assets meet “regulatory requirements”. Sparkpool notes, “Outage details will be sent through notifications, emails and on-site messages.

SparkPool was founded in China at the beginning of 2018 and, alongside the world’s largest Ethereum mining pool, Ethermine, has developed into one of the world’s largest mining pools for Ether (ETH) mining. At the time of writing, SparkPool’s mining power accounts for 22% of Ethereum’s global hash rate, slightly lower than Ethermine’s 24%, according to Poolwatch.io.

The news comes as the Chinese government reiterates its negative stance on cryptocurrencies and on Friday declared all crypto-related transactions in the country illegal. As a result, some of the largest crypto exchanges such as Binance and Huobi suspended registration of new accounts in mainland China and allegedly kept user services in Hong Kong.

Related: Ethereum falls more sharply than Bitcoin as China escalates crypto ban, ETH / BTC to 3-week lows

SparkPool did not immediately respond to Cointelegraph’s request for comment.

SparkPool’s failure comes as Ethereum continues its transition from a proof-of-work consensus mechanism to a proof-of-stake model in 2022 – part of a long-planned upgrade known as Ethereum 2.0. As previously reported by Cointelegraph, after the final rollout of Ethereum 2.0, Ether miners won’t have many options because their mining equipment is out of date.