On Saturday, more than 130 people in a train station in Kunming, China, were injured when about ten men and women wielding knives began stabbing others at random, the BBC reports. The attackers, who authorities say might be members of a Muslim separatist group from Xinjiang province, used swords and meat cleavers to inflict damage on people lined up near the busy station's ticket counter. Officials stated that at least 28 people have been confirmed dead as a result of the attacks, Reuters reports.

As shocking as Saturday's attack is, knife attacks are not uncommon in China. As Quartz reports, knives are often the weapon of choice there. Here's Quartz:

It’s unclear exactly how many knife attacks have taken place in China over the years, but the almost regular media reports of the attacks suggest that efforts to regulate the purchase of knives or punish offenders haven’t been successful.

Most recently, targets for these knife attacks have included schools and shopping centers. Last June, knife-wielding assailants killed nine policemen and 17 civilians at a police station in Lukqun Township in Xinjiang. In July of 2013, a mentally ill man stabbed four people, leaving a two-year-old boy dead, outside of a Carrefour shop in Beijing with a knife he purchased from the store. The following month, another man stabbed several passengers on a bus in Henan province, killing three, including a 10-month old baby and a 10-year-old child.

China is not unique in its problem with knives, however. In Japan, in 2001 a janitor wielding a kitchen knife killed eight children at an Osaka school where he worked, while a man in Tokyo went on a random stabbing spree with a dagger in 2008, killing four people. In South Korea, a disgruntled man killed eight people in a stabbing spree at his apartment complex in 2008. In Germany, a drunk 16-year-old stabbed 41 people at the opening ceremony of a Berlin train station. And last year, anti-knife campaigns ramped up in the U.K after a 13-year-old girl was stabbed to death.

All of these countries have tight gun control laws, and rates of violent crime involving knives reflect that. According to the United Nations Office of Drugs and Crime, firearms account for 76 percent of homicide weapons in the Americas (30 countries), while knives make up just 10 percent of those crimes. In Europe (32 countries), on the other hand, guns are involved in 36 percent of murders and knives are involved in 43 percent. Here's the U.N.:

Over the whole age range, a male in the Americas is around six times more likely to be killed by a firearm than a knife. In contrast, in 17 countries in Asia, firearm and sharp object homicides are much more equally distributed in the 15 to 34 age group: while a slightly higher proportion of violent deaths are caused by firearm in each group, a male in the countries examined in Asia is almost as likely to be killed by a knife as a firearm.

Likewise, deaths among European men are about evenly divided between guns and sharp objects, the U.N. reports. While either a gun or a knife is, clearly, a potential murder weapon, there is a correlation between the availability of guns and the lethality of violent crimes, the U.N. writes.