YouTube Blocks Campaign Account of Hong Kong’s Leader-in-Waiting

HONG KONG—Google’s YouTube blocked the campaign account of Hong Kong’s only leadership candidate, citing U.S. sanctions, in a move that ratchets up tensions between big tech companies and the city’s government amid a national-security crackdown on political opposition.

Mr. Lee, a former policeman and government security chief, is poised to become Hong Kong’s next top official in a small-circle election to be held May 8 by a committee of around 1,500 mostly Beijing loyalists and closely orchestrated by China’s central government. Mr. Lee first declared his candidacy for Hong Kong’s top office on April 9 in a live stream posted to both Facebook and YouTube.