The move came in the wake of rising community infections in neighboring countries, especially Cambodia, which has been suffering its largest wave of Covid-19 community transmissions.

The department suggested heightened transport inspections in the south-west border area of Vietnam alongside Cambodia, Lao Dong newspaper quoted Do Ngoc Hai, head of the department's road transport management, as saying.

Early on Wednesday, a group of Vietnamese, two women and a man, had crossed into Tay Ninh Province via an unmarked route. The trio then took a taxi from the province's Tan Bien Town to Ho Chi Minh City. The taxi driver, learning they had come from a pandemic-hit area, immediately returned to Tan Bien and contacted health authorities to be tested.

The trio had then taken another taxi to the airport and flown to Hanoi the same day before traveling to their hometown in the north. All have since been identified, sent to centralized quarantine facilities, and tested negative once for the new coronavirus.

HCMC authorities are currently tracing those who had come in contact with the trio from the moment they had entered the city.

Cambodia has been suffering a spike in infections following its latest Covid-19 wave that hit late February. Its caseload had jumped to 8,193 with 59 deaths as of Friday.

Of its total cases, there had been only around 400 infections until last year.

Vietnam shares a 1,137-kilometer border with Cambodia running along the provinces of An Giang, Dong Thap, Kien Giang, and Long An in Mekong Delta, Binh Phuoc and Tay Ninh near HCMC and Kon Tum, Gia Lai, Dak Lak, and Dak Nong in the Central Highlands.

As per Covid-19 prevention protocol, everyone entering Vietnam from abroad is quarantined for 14 days and tested at least twice.

For almost a month now Vietnam has not had any community transmission, though the number of imported cases has been gradually increasing, including many from Cambodia.