HONG KONG – Stocks in Hong Kong headed for their biggest weekly slide of 2017 and volatility surged as U.S. President Donald Trump stepped up pressure on North Korea.

The Hang Seng Index fell for a third straight day for the first time since June and was in line for a weekly drop of 2.3%, the most since December. Tencent Holdings Ltd. had its biggest drop in a month as investors took profit in some top performers.

The HSI Volatility Index, which measures expected price swings on the Hong Kong benchmark, surged 17% as it headed for its biggest weekly gain since January 2016. The Hang Seng China Enterprises Index tumbled toward its biggest loss of the year and the Shanghai Composite Index also declined.

“All the investors are screaming, ‘where’s the door?”’ said Andrew Clarke, director of trading at Mirabaud Asia Ltd. in Hong Kong. “Hong Kong has been a market where it’s all in or all out — retail clients are taking big profits.”

Tencent fell 3.9% , the most since July 4, after a selloff in technology stocks in the U.S. and as it emerged the company is being investigated for cyber-security law violations. Other outperformers this year also hit the brakes, with Geely Automobile Holdings Ltd. and AAC Technologies Holdings Inc. falling more than 2.5%.

Hong Kong Exchanges & Clearing Ltd continued its slide from Thursday, when China Merchants Securities Co. was among those to downgrade the company to sell.

Markets across Asia were down after U.S. President Donald Trump issued another warning to North Korea, promising a response to any strike against America or its allies. U.S. equities sold off the most since May on Thursday, sparking an unprecedented rush for protection in the options market.

Tencent was the biggest drag on the Hang Seng Index. Investors took profit after a tech stock selloff in the U.S. and to avoid earnings uncertainty, according to Richard Ko, an analyst at China Merchants Securities Co. A measure of technology companies was among the biggest decliners on the Hang Seng Composite Index, with BYD Electronic International Co. and IGG Inc. tumbling more than 5.5%.

HKEX slid 2.9% and was headed for a weekly drop of 7%, the most in nearly two years. Market turnover in the city is unlikely to stay strong, according to Jerry Li, a Hong Kong-based analyst with China Merchants Securities.

Volume on the Hang Seng Index was 88% more than its 30-day intraday average, according to data compiled by Bloomberg. On the mainland, a measure of materials companies fell the most on the CSI 300 Index, with China Molybdenum Co. and Aluminum Corp. of China dropping more than 6%.

The subindex has jumped 25% this year, more than twice the gains by the broader gauge.Ping An Bank Co. slumped 5% in Shenzhen after earnings showed little improvement in asset quality and a narrowing net interest margin. The CSI 300 Index fell 1.4% and the Shenzhen Composite Index lost 0.8%.

– Bloomberg