Seven districts in Shanghai have reached zero-COVID status, local officials said on Friday, one day after announcing over 70 percent of the companies that were prioritized to reopen, have already done so.

The eastern Chinese city has been fighting a tough battle against the worst outbreak in the city in two years, but daily positive cases have been dipping steadily for over a week, sending relief to businesses and many people who were quarantined for more than a month. 

The city registered 245 locally transmitted symptomatic cases and 4,024 asymptomatic cases on Thursday, taking the total number of positive cases to 597,424 since March.

Jiading District, which obtained the status on Thursday, has joined six other districts that had earlier eliminated the virus.

The Shanghai government has designated residential units home to over 16 million people as "prevention areas," which allow them to venture out of their communities with certain rules attached.

Some 6.6 million people are still required to either stay at home or within their communities.

With an improving COVID situation, the Chinese financial hub has been ramping up efforts to have companies resume work. As of Thursday, around 70 percent of the over 1,800 firms that local authorities decided were a priority, had reopened. 

Twelve COVID-related deaths were recorded on Thursday, the authorities said.