Vietnam has reported 28 new Covid-19 infections and two deaths, bringing total cases to 670, with eight dead, as the capital Hanoi said it lacked the rapid testing kits it needs to continue mass screening for cases amid a new outbreak.

Most of the new cases are linked to Danang, the health ministry said, adding there were over 133,000 people undergoing quarantine, about 80 per cent of those in their homes.

More than 88,000 people have returned to Hanoi from Danang since July 8, but only 70,689 were tested, authorities said, with two positive cases.

The gap is due to a shortage of rapid testing kits used to screen thousands of residents at a time, according to state media. Hanoi medical institutions and hospitals have been assigned to boost testing capacity.