(Adds banks' statements; rewrite headline)
SHANGHAI, June 21 (Reuters) - China's central bank said on Monday it had recently summoned some banks and payment firms, including China Construction Bank and Alipay, urging them to crack down harder on cryptocurrency trading.
The People's Bank of China's meeting came after China's State Council, or cabinet, last month said it would tighten restrictions on bitcoin trading and mining. Beijing has sharply ratcheted up its campaign in the last few weeks.
The PBOC urged institutions at the meeting to launch thorough checks on clients' accounts to identify those involved in cryptocurrency transactions, and promptly cut their payment channels. It did not mention when the meeting was held.
"Speculative trading in virtual currencies roils economic and financial order, spawns the risks of criminal activities such as illegal asset transfers and money laundering, and endangers people's wealth," the PBOC said in a statement.
Other participants in the PBOC's meeting included state-owned lenders Industrial and Commercial Bank of China (ICBC) , Agricultural Bank of China (AgBank) and Postal Savings Bank of China .
Bitcoin's bull run globally had revived speculative trading in China, where people buy cryptocurrencies using yuan via bank accounts or payment platforms.
Last month, three industry associations issued a ban on crypto-related financial services, but the bodies are much less powerful than the PBOC.
The PBOC said its recent meeting with financial institutions was aimed at fully implementing State Council's crypto ban.
Bitcoin tumbled almost 10% on Monday, with market players citing jitters over China's expanding crackdown on bitcoin mining in thin liquidity for the losses. It was last down 8.3%, on course for its biggest daily drop in a month.
KNOW YOUR CUSTOMER
The PBOC asked banks and payment companies to invest more in technologies used to better identify crypto-related transactions, and know their customers better, the central bank statement said.
After the central bank's notice, AgBank, ICBC, CCB and Alipay vowed to execute what they were told to do.
AgBank said that it would conduct due diligence on clients to root out illegal crypto-related activities and shut down suspicious accounts.
Alipay, the ubiquitous payment platform owned by fintech giant Ant Group, said in a separate statement that it would set up a regulator monitoring system targeting key websites and accounts to detect illegal crypto-related transactions.
Alipay added it would blacklist any merchants involved in virtual currency transactions.
Alipay and Tencent-owned Wechat Pay had been listed as means of payment on the websites of some over-the-counter markets, where Chinese individuals buy cryptocurrencies with the Chinese yuan
ICBC, China's biggest lender, cautioned the public in a statement against the risks of cryptocurrency trading and initial coin offerings (ICOs).
As China ramped up its campaign against cryptocurrencies in recent weeks, bans on cryptomining have been issued in major bitcoin mining hubs, including Sichuan, Xinjiang, and Inner Mongolia.
Cryptomining is a big business in China, which accounts for over half of global bitcoin production.
China has also blocked a slew of cryptocurrency-related social media accounts, and barred the search for major cryptocurrency exchanges such as Binance and Huobi on baidu.com and Twitter-like platform Weibo. (Reporting by Shanghai Newsroom; Editing by Sumeet Chatterjee and Alex Richardson)
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