The decision, which took immediate effect Wednesday, was taken after the Health Ministry consulted experts on ways to keep the larger community safe, said Minister Nguyen Thanh Long.

The decision has been made after several individuals contracted the virus after they'd already completed the 14-day quarantine and tested negative twice or thrice.

In the past week, at least three such cases have been detected.

The latest decision is the second reversal in as many days. The ministry had said a day earlier that those in centralized quarantine facilities would not be allowed to go home after completing the mandated 14-day quarantine and testing negative twice during the period. It had not specified the new duration.

Then, it reversed the decision earlier today, saying the original 14-day quarantine period will remain with strengthened post-quarantine monitoring and restrictions.

Minister Long has urged concerned facilities to impose quarantine procedures strictly to prevent contagion. A person who has completed the 21-day quarantine needs to be supervised for the next seven days at home, he said.

He also asked localities to find and conduct random tests for foreigners who have entered Vietnam recently, as well as employees of bars, karaoke and massage parlors.

Vietnam has confirmed 38 new local Covid-19 cases since April 27 in the latest outbreak, the northern provinces of Ha Nam and Vinh Phuc leading with 14 cases each, followed by Hanoi with four.