The Chinese port city of Qingdao has reported 88 new coronavirus cases in the last 24 hours, all of them of the Omicron variant, fuelling China's highest number of daily locally transmitted cases so far this year, Reuters reports.

The Qingdao outbreak was mainly among middle school students in Laixi county, the Qingdao Municipal Health Commission said.

Laixi county will implement a second round of mass testing on Monday, a Qingdao official said at a news conference on Sunday, adding that there was no major risk of a further outbreak.