A woman helps a girl write on a memory board to mourn victims of a mass shooting in front of an outlet mall in Allen, Texas, the United States, on May 8, 2023. [Photo/Xinhua]

NEW YORK - The latest series of mass shootings in the United States has led to several countries issuing warnings over gun violence for travelers heading to US destinations, reported Newsweek on Tuesday.

According to the Gun Violence Archive, a website that monitors and collects information about shootings across the country, there have been 21 mass shootings -- defined as one incident in which at least four people are shot and either injured or killed -- between May 1 and 7.

Since the beginning of the year, there have been 208 mass shootings across the country, the Gun Violence Archive reports. Nearly 15,000 people have lost their lives in gun violence-related incidents in the United States this year.

"The number of such incidents in the US is reflected by the level of alarm over gun violence in America in countries like Canada, Australia and the UK, which mention such concerns in their travel warning," said the report.

For example, in its advice to travelers heading across the American border, Canadian authorities write about the high rate of firearm possession in the United States, noting that it is "legal in many states for citizens to openly carry firearms in public."