HANOI (REUTERS) - Vietnam on Friday (March 6) reported its first new coronavirus case in three weeks but the risk of infections spreading remains very high, Hanoi city chairman Nguyen Duc Chung said.

Nguyen Hong Nhung, a 26-year-old woman, was admitted to a hospital in the Vietnamese capital on Thursday suffering from fever, Chung told a news conference.

Nhung had returned on Monday from a trip to Europe during which she visited London, Milan and Paris, according to Chung.

"The risk of the virus spreading is very high, and we need to stay vigilant but not to panic," Chung said.

Nhung arrived in London on Feb 16, flew on to Milan on Feb 18 before returning to London on Feb 20, according to a Hanoi Department of Health statement. Milan is in Italy's north, the heart of Europe's worst coronavirus outbreak.

On Feb 25, Nhung went to Paris and returned to London the following day, the statement said.

She flew back to Vietnam on a Vietnam Airlines flight early on Monday.

The South-east Asian country has reported 17 people, including Nhung, with coronavirus infections to date, 16 of whom have been cured and released from hospitals.

There have been no deaths.

More than 100,000 cases have been reported in over 90 countries worldwide, with more than 3,400 deaths, wreaking serious economic damage.