The city government of Suzhou, a center for smartphone manufacturing and other high-tech industry west of Shanghai, told its 18 million people to stay home when possible.

Taiyuan, a blue-collar city of 4 million in central China, suspended inter-city bus service, according to the official China News Service. Ningde in the southeast barred residents from leaving.

A restaurant cook in Taiyuan said his family has been confined to their apartment compound since April 3 after cases were found in neighboring compounds.

“Our lives will be seriously affected if the restrictions last long,” said the cook, who would give only his surname, Chen.

“My wife and I are earning nothing,” Chen said. “We have three children to support.”

All but 13 of China’s 100 biggest cities by economic output are under some form of restrictions, according to Gavekal Dragonomics, a research firm.