A foreign woman wears a mask as she walks her dog along the
West Lake in Tay Ho District, Hanoi, 2019. Photo by VnExpress/Ngoc Thanh. 

Police in Hanoi's Tay Ho District said a gang of 25 men is suspected of carrying out violent attacks, including sexual, on foreign women strolling around West Lake. 

They have appealed to victims to help identify the culprits, Vietnam News Agency quoted a police source as saying.

They said the gang is comprised of young men always traveling on motorbikes.

The police recently received complaints from a group of foreign women that they were attacked violently, with the attackers throwing bricks at them or hitting them with belts.

Following the attacks, expats have created a Facebook group called Hanoi Nightwatch as a platform to report cases of sexual assault and suggest ways in which members can protect themselves. It has over 4,200 members.

The U.K. Embassy in Hanoi also warned British citizens on its official Facebook page: "We are aware that there has been a recent spike in reports of personal attacks, including rape and sexual assault, on foreign nationals in Hanoi. Some reports are of women being victims of indecent assault and harassment including inappropriate touching and groping."

Foreign Ministry spokeswoman Le Thi Thu Hang said at a press briefing last week that her ministry would discuss with relevant Vietnamese agencies to verify the information and deal with cases mentioned by the U.K. Embassy.

"We affirm that Vietnam always pays attention to ensuring security, order and safety for Vietnamese people and the expat community in Vietnam and strictly deals with lawbreakers."

Some 91,000 foreigners from more than 100 nations and territories live and work in Vietnam, mainly in HCMC and Hanoi.