Mainland China reported 30 new coronavirus cases on Saturday, up from 19 a day earlier as the number of cases involving travellers from abroad as well as local transmissions increased, highlighting the difficulty in stamping out the outbreak.

The National Health Commission said in a statement on Sunday that 25 of the latest cases involved people who had entered from abroad, compared with 18 such cases a day earlier. Five new locally transmitted infections were also reported on Saturday, all in the southern coastal province of Guangdong, up from a day earlier.

The mainland has now reported a total of 81,669 cases, while the death toll has risen by three to 3,329.

Though daily infections have fallen dramatically from the height of the epidemic in February, when hundreds of new cases were reported daily, Beijing remains unable to completely halt new infections despite imposing some of the most drastic measures to curb the virus’ spread.