Preliminary investigations revealed that five men and four women from China illegally entered Vietnam through Quang Ninh Province on April 1 and traveled to Hanoi and met Nguyen Thanh Lam, 26, the man currently held.

The next day he took them by taxi to Dong Hoi Town in the central Quang Binh Province where they stayed in a motel.

A day later he moved them to another motel to avoid detection by local authorities.

But in the early hours of April 5 local police stopped them as they were getting into taxis to leave for Quang Tri Province, around 150 kilometers away.

They were unable to furnish entry papers, and were sent to quarantine as mandated by the Health Ministry.

Lam said he had been paid VND25 million ($1,081) to take the illegals to Quang Tri.

The police said Lam and the Chinese tested negative twice for Covid-19.

After completing the 14-day quarantine, the nine will be deported.

While Vietnam has sealed its borders, there are occasional illegal entrants who evade checkpoints to avoid the mandatory quarantine.

For around three weeks now there has been no community transmission of Covid, but health experts warn Vietnam must be on high alert for possible spread of infection by illegal entrants.