With the exception of factories producing medical protective equipment, which the Chinese government has asked to run around the clock, few businesses seem to be returning yet to their previous pace.

Toyota said that its four assembly plants had operated on two work shifts a day before the virus spread. But it planned to reopen three of them on Monday and Tuesday with just one shift and leave closed for now the fourth and smallest, in the western Chinese city of Chengdu.

Foxconn, the Taiwan company that makes iPhones and other gadgets on behalf of Apple and global electronics companies, declined to detail which plants have reopened since the Chinese holiday ended but denied a media report that it was aiming to reach 50 percent production levels by the end of this month. It did not respond to requests for additional comment. Apple also declined to comment, but its chief executive, Timothy D. Cook, said last month, without offering specifics, that some of its suppliers could be disrupted.

China’s consumer electronics components factories slowly reopened through last week, and by Monday practically all had reopened except those in Wuhan, at the center of the epidemic, said Anna-Katrina Shedletsky, the chief executive of Instrumental, a remote quality monitoring system used by global brands to track and manage electronics manufacturing. She added, however, that many of these factories were not at full production.

The American Chamber of Commerce in Shanghai, which has members across much of the industrial heartland in east-central China, said that the majority of its members had restarted at least some operations. But the bulk of these members are not at full production, mainly for lack of workers, said Ker Gibbs, the chamber’s president.

The reopening of businesses means trying to bring together again much of China’s 700 million-strong labor force after what had become a nearly three-week national holiday. China’s containment efforts have effectively carved up the country. At least 760 million people — slightly over half the country’s population — are under various kinds of lockdown.

The authorities have begun trying to reconnect the country. China’s agriculture ministry demanded over the weekend the removal of road and highway blockages in rural areas that have prevented the movement of livestock and animal feed. The southern province of Jiangxi announced last Thursday that it would dismantle checkpoints at highway entrances and exits.