BEIJING (REUTERS) - The Chinese city of Tianjin, with around 14 million people, has tightened exit controls and now requires residents to obtain approval from employers or community authorities before leaving town and a negative Covid-19 test within 48 hours of departure.

The northern coastal city reported 21 domestically transmitted cases with confirmed symptoms on Sunday (Jan 9), the National Health Commission said on Monday, up from three a day earlier.

Tianjin said that over the weekend, it detected two local infections who had contracted the Omicron coronavirus variant. The city government announced the new exit rules in a statement late on Sunday.

In the central Henan province, the city of Anyang detected two local Omicron infections. The city's outbreak could be traced back to a student arriving from Tianjin, a local paper backed by the Communist Party authority in Anyang said on Monday.

It remained unclear how many other local cases in Tianjin and Anyang were related to Omicron.

Anyang, with 5.5 million residents, suspended all its bus services from Sunday.

Nationwide, mainland China reported 97 local symptomatic cases for Sunday, up slightly from 92 a day earlier, with 60 in Henan.

The city of Xi'an, where the local authorities are planning the gradual resumption of parcel deliveries and some businesses, reported 15 local symptomatic cases.

There were no new deaths for Sunday, leaving the death toll unchanged at 4,636. Mainland China had 103,776 confirmed symptomatic cases as at Jan 9, including both local and imported ones.