By Khanh Vu and Phuong Nguyen
HANOI (Reuters) - Vietnam reported 28 new COVID-19 infections and two deaths on Tuesday, 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.
Targeted testing and strict quarantining had helped Vietnam contain earlier outbreaks, but it is now battling new infections after going more than three months without any domestic transmission.
The new outbreak has infected more than 220 people since July 25, the majority in Danang, but it has spread to at least eight other cities and provinces, including Hanoi and Ho Chi Minh City, where entertainment venues are closed and gatherings restricted to prevent infections.
Danang and Buon Ma Thuot in the coffee-growing Central Highlands are on lockdowns. A government spokesman on Monday there was no plan for a nationwide lockdown.
Vietnam's government said on Tuesday the Danang outbreak appears to have started in early July.
Most of Tuesday's new cases are linked to Danang, the health ministry said, adding there were over 133,000 people undergoing quarantine, about 80% 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.
Rapid tests can diagnose a blood sample in minutes but are prone to inaccuracies. They are used to identify potentially positive cases that are confirmed using the more accurate, swab-based Polymerase Chain Reaction (PCR) test.
Phan Quoc Viet, chairman of PCR test kit manufacturer Viet A Corp, said he was not concerned about stocks.
"Vietnam is not short of COVID-19 test kits," Viet told Reuters. "We have enough for two million PCR tests and are willing to provide enough kits for the country to conduct a widespread testing programme".
(Reporting by Khanh Vu and Phuong Nguyen; Writing by James Pearson; Editing by Martin Petty and Gareth Jones)