Five of them were discovered by police in Lao Cai Province bordering China at 1 a.m. Monday while they were in a car. Two Vietnamese citizens, Duong Dinh Quyen and Nguyen Thanh Cuong, took turns to drive the car.

At the police station, Quyen and Cuong said they were hired in Nha Trang in the central province of Khanh Hoa to travel more than 1,500 km to Lao Cai, pick up the five Chinese citizens and bring them to Nha Trang.

Based on their statements, Lao Cai police informed the traffic police tasked with overseeing the Noi Bai - Lao Cai highway connecting the two cities to find a car that was driving five other Chinese citizens the same day with a driver and an assistant from Nha Trang.

The Chinese group had hired Vietnamese citizens for around VND500,000 ($21.66) to help them cross the Nanxi River, a tributary of the Red River in China's Yunnan Province, and enter Muong Khuong District in Lao Cai.

The foreigners had come to Vietnam to work at factories in Nha Trang and Da Nang, police said, without giving further details.

Earlier this month, a criminal probe was launched into three Vietnamese brokering illegal entry to Vietnam after they helped four Chinese nationals cross the border into Lao Cai Province.

On Saturday, Vietnamese police arrested a Chinese man involved in a ring bringing Chinese nationals into Da Nang and the neighboring Quang Nam Province illegally.

The country has banned entry by foreign nationals since March 22 with exceptions and conditions, including 14-day quarantining on arrival.